CSAT and SLA measure two different things: how customers feel about the support they got, and how consistently your team hit the deadlines you set for yourselves. Both are worth watching closely, since they tend to catch different kinds of problems.
How CSAT ratings are collected
After a conversation is resolved, the customer can rate their experience on a simple 1 to 5 scale from a link, without needing to log in or install anything. Every rating rolls up into the CSAT report, so you can see trends over time rather than just individual scores.
How SLA performance is measured
SLA policies are set per inbox, and every conversation is tracked against its deadline automatically. The SLA report shows how often your team is meeting those deadlines, and where breaches are happening, by inbox or by teammate.
Using both together
A low CSAT score alongside frequent SLA breaches usually points to the same root cause, your team being stretched too thin. Watching them together often tells a clearer story than either one alone.