Core Core is the set of software required to run WordPress. The Core Development Team builds WordPress.
Accessibility Accessibility (commonly shortened to a11y) refers to the design of products, devices, services, or environments for people with disabilities. The concept of accessible design ensures both “direct access” (i.e. unassisted) and “indirect access” meaning compatibility with a person’s assistive technology (for example, computer screen readers). (https://en.wikipedia.org/wiki/Accessibility)
Meta Meta is a term that refers to the inside workings of a group. For us, this is the team that works on internal WordPress sites like WordCamp Central and Make WordPress.
CLI Command Line Interface. Terminal (Bash) in Mac, Command Prompt in Windows, or WP-CLI for WordPress.