An SLA policy sets time targets for how quickly a ticket should receive a first response and how quickly it should be resolved. These targets are usually tied to priority, so urgent tickets get tighter deadlines than low-priority ones.
Business hours define when your team is actually working - the days, hours, and timezone SLA calculations should count against - so a ticket submitted overnight or over a weekend does not unfairly count against your response time.
As a deadline approaches or is missed, CLASP can escalate the ticket so it gets attention before or immediately after a breach occurs.