APR (annual percentage rate) is the simple, non-compounded rate at which rewards accrue over a year. APY (annual percentage yield) factors in compounding — reinvesting rewards as they arrive — which produces a higher headline number for the same underlying reward rate, especially on networks that distribute rewards frequently.
Different platforms compound at different frequencies (some daily, some per epoch, some not at all without manual restaking), so a fair comparison requires knowing which figure a page is quoting and how often compounding actually happens in practice. Auto-compounding liquid staking tokens tend to show APY; a validator's own dashboard often shows APR.
On this site, figures sourced from on-chain yield data are shown as reported by the data provider and refreshed regularly; always confirm the exact methodology on the provider or protocol's own page before making a decision, since definitions vary and real, realized returns depend on validator uptime, commission, and network conditions that change over time.