Compound interest rate: aTokens pay out interest per ~1second. This means also your interest on that interest compounds per second increasing the compound interest effect over traditional yearly/quaterly payouts.
Archived deposit rate:Aave deposit rate is based on the assets borrow utilization & flash loan usage. As you can see in the chart above, for some assets the deposit rate is relatively stabe, while for others it is very volatile. To get a rough impression of what to expect as a deposit rate you might want to check historical data.