Continuous Integration (CI) is the practice of developers frequently merging their code into a shared repository, where each integration is automatically verified (built and tested). It catches problems early and keeps the codebase in a healthy, working state.
The core practice
Developers integrate code FREQUENTLY (at least daily) into the shared/main branch:
→ each integration is AUTOMATICALLY built and tested (by a CI server/pipeline)
→ problems are caught IMMEDIATELY (on each small change, not after weeks)
→ vs the old way: developers work in isolation for long periods → painful "integration
hell" when finally merging diverged work (many conflicts, surprises, bugs).
