An integrated development environment brings common software-development activities into one application. It usually includes a source-code editor, project navigation, language support, debugging and integrations for tests, version control and deployment tools.
AI features can be delivered through an IDE extension or built directly into the environment. Extensions may connect to a model provider through a bundled agreement or a user's API key, which affects model availability, usage limits and where charges are applied.
ELI5
An integrated development environment is an application that puts common software-building tools in one workspace. It usually combines code editing, project navigation, debugging, testing, and version-control features.
For example, a developer can edit a function, run its tests, inspect an error, and review the changed files without leaving the environment. AI assistance may be built in or added through an extension with its own provider and usage rules.

