WordPress
WordPress is the world's most popular open-source CMS, powering over 43% of all websites. It started as a blogging platform in 2003 and evolved into a full-featured content management system with a massive plugin ecosystem, theme marketplace, and a global developer community.
§ 1 Definition
WordPress is an open-source Content Management System written in PHP. It powers 43%+ of all websites on the internet and holds roughly 62% market share among known CMS platforms. Launched in 2003 as a fork of b2/cafelog, WordPress evolved from a blogging tool into a full CMS capable of running everything from personal blogs to enterprise ecommerce stores. WordPress is distributed under the GPLv2 license, meaning it's free to use, modify, and distribute. The ecosystem includes thousands of Plugins (extending functionality), Themes (controlling design), and a global community of developers, agencies, and contributors. Recent development has focused on Full Site Editing (FSE) and the Gutenberg Editor, shifting WordPress toward a block-based content architecture.
§ 2 History and Market Position
WordPress was released in May 2003 by Matt Mullenweg and Mike Little as a fork of the b2/cafelog blogging system. Version 1.0 arrived in January 2004. By 2011, WordPress powered over 13% of the top million websites. Today it commands 43%+ of all websites surveyed by W3Techs. However, that dominance is slowly eroding. WordPress's CMS market share peaked at 65.2% in 2022 and has declined to roughly 62% in 2025. SaaS builders like Wix, Squarespace, and Shopify are absorbing new site launches, while headless CMS platforms like Sanity and Contentful are winning technically sophisticated teams. Still, WordPress's ecosystem is unmatched. Over 59,000 free plugins, thousands of themes, and a developer community spanning every time zone mean you can build almost anything on WordPress. The question is whether you should.
§ 3 Core Architecture
WordPress follows a monolithic CMS architecture. The content management backend and the frontend presentation layer live in the same codebase. Here's how the stack works: - Database: MySQL or MariaDB stores posts, pages, users, options, and metadata - PHP Backend: Core WordPress files handle routing, database queries, authentication, and the admin dashboard - Theme Layer: Template files (PHP + HTML + CSS) control how content is rendered - Plugin Layer: Extensions hook into WordPress actions and filters to modify behavior without touching core files - REST API: Introduced in 4.7, the WordPress REST API allows external applications to interact with WordPress content programmatically, enabling headless WordPress setups The template system uses a Template Hierarchy that determines which PHP file renders a given request. Custom Post Types and Taxonomies extend the default content model beyond posts and pages.
§ 4 WordPress.com vs WordPress.org
This distinction confuses almost everyone at first. Here's the difference: - WordPress.org (self-hosted): You download the software, find your own hosting, and have full control over everything. You can install any theme or plugin, modify code, run ecommerce, and monetize however you want. This is what Atomic Glue works with. - WordPress.com (hosted SaaS): Automattic (the company behind WordPress core) runs the infrastructure. Free and paid tiers exist. You trade control for convenience. Business and Commerce plans unlock plugin installation and theme uploads, but you still operate within Automattic's walled garden. If you're building a serious website, use WordPress.org. WordPress.com is fine for a personal blog where you don't want to manage hosting.
§ 5 Common WordPress Issues
WordPress's greatest strength (its plugin ecosystem) is also its greatest vulnerability. Common problems include: - Plugin bloat: Running too many plugins slows your site and creates security surface area - Security risks: Outdated core, themes, or plugins are the most common attack vectors - Performance degradation: Default WordPress can be slow without caching, CDN, and image optimization - Update conflicts: Plugin or theme updates can break each other, requiring careful staging and testing - Spam: Comment spam and registration spam require active management None of these are dealbreakers. They're maintenance responsibilities. Our WordPress maintenance service at $149/month handles updates, security monitoring, backups, and performance optimization so you don't have to.
§ 6 Common questions
- Q. Is WordPress free?
- A. The WordPress software is free and open source. You pay for hosting, a domain name, and optionally premium themes, plugins, or developer help.
- Q. Is WordPress good for ecommerce?
- A. Yes, with WooCommerce. WordPress plus WooCommerce powers a significant portion of online stores. For large catalogs or complex B2B, Shopify or BigCommerce may be better fits.
- Q. Is WordPress secure?
- A. WordPress itself is secure when properly maintained. Most breaches come from outdated plugins, weak passwords, or poorly coded themes. Regular updates and good security practices are mandatory.
- WordPress powers 43%+ of all websites with the largest CMS ecosystem in existence.
- Self-hosted WordPress.org gives you full control; WordPress.com is a restricted SaaS version.
- The plugin and theme ecosystem is both WordPress's superpower and its biggest risk vector.
- Proper WordPress maintenance is not optional. Updates, backups, and security monitoring require ongoing attention.
We've been building and maintaining WordPress sites since the early days. Our WordPress maintenance plan at $149/mo handles updates, security, backups, and performance. For new builds, we architect custom WordPress solutions that don't rely on 50 plugins to function. Talk to us about your WordPress project.
Get in touchWordPress is the world's most popular open-source CMS, powering over 43% of all websites. It started as a blogging platform in 2003 and evolved into a full-featured content management system with a massive plugin ecosystem, theme marketplace, and a global developer community.
Category: Cms
Author: Atomic Glue Editorial Team
## Definition
WordPress is an open-source Content Management System written in PHP. It powers 43%+ of all websites on the internet and holds roughly 62% market share among known CMS platforms. Launched in 2003 as a fork of b2/cafelog, WordPress evolved from a blogging tool into a full CMS capable of running everything from personal blogs to enterprise ecommerce stores. WordPress is distributed under the GPLv2 license, meaning it's free to use, modify, and distribute. The ecosystem includes thousands of [Plugins](/glossary/plugins) (extending functionality), [Themes](/glossary/themes) (controlling design), and a global community of developers, agencies, and contributors. Recent development has focused on [Full Site Editing (FSE)](/glossary/full-site-editing-fse) and the [Gutenberg Editor](/glossary/gutenberg-editor), shifting WordPress toward a block-based content architecture.
## History and Market Position
WordPress was released in May 2003 by Matt Mullenweg and Mike Little as a fork of the b2/cafelog blogging system. Version 1.0 arrived in January 2004. By 2011, WordPress powered over 13% of the top million websites. Today it commands 43%+ of all websites surveyed by W3Techs. However, that dominance is slowly eroding. WordPress's CMS market share peaked at 65.2% in 2022 and has declined to roughly 62% in 2025. SaaS builders like Wix, Squarespace, and Shopify are absorbing new site launches, while headless CMS platforms like [Sanity](/glossary/sanity) and [Contentful](/glossary/contentful) are winning technically sophisticated teams. Still, WordPress's ecosystem is unmatched. Over 59,000 free plugins, thousands of themes, and a developer community spanning every time zone mean you can build almost anything on WordPress. The question is whether you should.
## Core Architecture
WordPress follows a monolithic CMS architecture. The content management backend and the frontend presentation layer live in the same codebase. Here's how the stack works: - **Database:** MySQL or MariaDB stores posts, pages, users, options, and metadata - **PHP Backend:** Core WordPress files handle routing, database queries, authentication, and the admin dashboard - **Theme Layer:** Template files (PHP + HTML + CSS) control how content is rendered - **Plugin Layer:** Extensions hook into WordPress actions and filters to modify behavior without touching core files - **REST API:** Introduced in 4.7, the WordPress REST API allows external applications to interact with WordPress content programmatically, enabling headless WordPress setups The template system uses a [Template Hierarchy](/glossary/template-hierarchy) that determines which PHP file renders a given request. [Custom Post Types](/glossary/custom-post-types) and [Taxonomies](/glossary/taxonomies) extend the default content model beyond posts and pages.
## WordPress.com vs WordPress.org
This distinction confuses almost everyone at first. Here's the difference: - **WordPress.org** (self-hosted): You download the software, find your own hosting, and have full control over everything. You can install any theme or plugin, modify code, run ecommerce, and monetize however you want. This is what Atomic Glue works with. - **WordPress.com** (hosted SaaS): Automattic (the company behind WordPress core) runs the infrastructure. Free and paid tiers exist. You trade control for convenience. Business and Commerce plans unlock plugin installation and theme uploads, but you still operate within Automattic's walled garden. If you're building a serious website, use WordPress.org. WordPress.com is fine for a personal blog where you don't want to manage hosting.
## Common WordPress Issues
WordPress's greatest strength (its plugin ecosystem) is also its greatest vulnerability. Common problems include: - **Plugin bloat:** Running too many plugins slows your site and creates security surface area - **Security risks:** Outdated core, themes, or plugins are the most common attack vectors - **Performance degradation:** Default WordPress can be slow without caching, CDN, and image optimization - **Update conflicts:** Plugin or theme updates can break each other, requiring careful staging and testing - **Spam:** Comment spam and registration spam require active management None of these are dealbreakers. They're maintenance responsibilities. [Our WordPress maintenance service](/wordpress-maintenance) at $149/month handles updates, security monitoring, backups, and performance optimization so you don't have to.
## Common questions
Q: Is WordPress free?
A: The WordPress software is free and open source. You pay for hosting, a domain name, and optionally premium themes, plugins, or developer help.
Q: Is WordPress good for ecommerce?
A: Yes, with WooCommerce. WordPress plus WooCommerce powers a significant portion of online stores. For large catalogs or complex B2B, Shopify or BigCommerce may be better fits.
Q: Is WordPress secure?
A: WordPress itself is secure when properly maintained. Most breaches come from outdated plugins, weak passwords, or poorly coded themes. Regular updates and good security practices are mandatory.
## Key takeaways
- WordPress powers 43%+ of all websites with the largest CMS ecosystem in existence.
- Self-hosted WordPress.org gives you full control; WordPress.com is a restricted SaaS version.
- The plugin and theme ecosystem is both WordPress's superpower and its biggest risk vector.
- Proper WordPress maintenance is not optional. Updates, backups, and security monitoring require ongoing attention.
## Related entries
- [CMS](atomicglue.co/glossary/cms)
- [WooCommerce](atomicglue.co/glossary/woocommerce)
- [Plugins](atomicglue.co/glossary/plugins)
- [Themes](atomicglue.co/glossary/themes)
- [Gutenberg Editor](atomicglue.co/glossary/gutenberg-editor)
- [Full Site Editing (FSE)](atomicglue.co/glossary/full-site-editing-fse)
- [WP-CLI](atomicglue.co/glossary/wp-cli)
- [Custom Post Types](atomicglue.co/glossary/custom-post-types)
- [Taxonomies](atomicglue.co/glossary/taxonomies)
- [Template Hierarchy](atomicglue.co/glossary/template-hierarchy)
Last updated July 2025. Permalink: atomicglue.co/glossary/wordpress