Service Level Agreement

A service level agreement (SLA) is a written promise about the standard of service one party will provide to another, put in clear, measurable terms. It might promise that support replies within four hours or that a website stays available almost all of the time, so both sides know what good looks like.

Think of it as a pizza shop guaranteeing delivery in thirty minutes or the meal is free: the promise is specific and you can check whether it was kept. A service level agreement matters because it turns vague expectations into something you can hold a supplier to, and sets out what happens when the promise is missed.