A service level agreement (SLA) is a contractual commitment between a provider and a customer specifying a measurable level of service — usually uptime percentage — and the financial penalties (service credits) if it is breached.
A typical SaaS SLA defines: the measurement window (monthly), the metric (uptime measured by the provider's own monitoring), what counts as downtime (excluding scheduled maintenance, force majeure, customer-caused issues), and the credit schedule (e.g. 10% credit if uptime drops below 99.9%, 25% if below 99%, 100% if below 95%).
SLA reports are usually self-reported by the vendor unless the customer runs independent monitoring against the same endpoints — which is why third-party uptime monitoring exists.
An SLA without independent measurement is just marketing copy. Running your own uptime monitor against your vendors gives you the evidence you need to claim service credits when they breach.
See it in the product: Status pages.