What the words mean, explained without the marketing — and the part the vendor documentation leaves out.
Most terms in this space were named by the vendor that shipped the feature, which means the definition and the marketing arrived together. These pages separate them: what the thing actually is, what problem it solves, and what the documentation leaves out.
Every definition here is written for someone with a real repository, not for someone deciding whether the field is interesting.
Where a term is genuinely new and unsettled, we say that rather than pretending there is consensus.
A definition that covers everything explains nothing. Each page states what the thing is not, because that is usually the part people get wrong.
We explain how it works, not what it is like. Analogies are how you end up with a mental model that fails exactly when it matters.
Every feature in this space has a threshold below which it is overhead. We give the threshold.
what is mcp server in ai — what it means for a repo with real invariants, not a demo.
mcp server meaning — what it means for a repo with real invariants, not a demo.
github copilot skills — what it means for a repo with real invariants, not a demo.
github copilot sdk — what it means for a repo with real invariants, not a demo.
git worktree claude code — what it means for a repo with real invariants, not a demo.
gemini cli skills — what it means for a repo with real invariants, not a demo.
copilot api — what it means for a repo with real invariants, not a demo.
cline memory bank — what it means for a repo with real invariants, not a demo.
claude code worktrees — what it means for a repo with real invariants, not a demo.
claude code system prompt — what it means for a repo with real invariants, not a demo.
claude code subagents — what it means for a repo with real invariants, not a demo.
claude code sdk — what it means for a repo with real invariants, not a demo.
claude code sandbox — what it means for a repo with real invariants, not a demo.
claude code router — what it means for a repo with real invariants, not a demo.
claude code permissions — what it means for a repo with real invariants, not a demo.
claude code memory — what it means for a repo with real invariants, not a demo.
claude code hooks — what it means for a repo with real invariants, not a demo.
claude code context window — what it means for a repo with real invariants, not a demo.
claude code commands — what it means for a repo with real invariants, not a demo.
claude code api key — what it means for a repo with real invariants, not a demo.