A pair or duo; two people (or things) acting together. Often used for comedy duos.
あの二人は人気のコンビだ。
Those two are a popular comedy duo.
彼と私でコンビを組んでプロジェクトを進める。
He and I will form a pair and work on the project together.
お笑いコンビがテレビに出ている。
A comedy duo is appearing on TV.