A Mac can join Wi-Fi and still fail to reach the internet. Apple lists renewing the DHCP lease as one troubleshooting step for an address assigned by the network. It is a narrower action than forgetting a saved network or resetting a router, and it does not fix every connection problem.
Check the connection you will change
Open System Settings → Network, select the relevant network service and open Details. Under TCP/IP, choose Renew DHCP Lease, then confirm with OK. These instructions apply when the service receives its address through DHCP. If the network uses a manually assigned address or managed settings, check with its administrator before changing anything.
Renewing asks the DHCP server to renew the current assignment. The resulting address does not have to be different. Do not treat an unchanged address as evidence that the operation failed, and do not type an arbitrary manual address to force a change.
Test the actual task
After renewal, retry the page or application that failed and check whether other internet tasks work. For example, open one known working page and then the original page. If only the latter fails, the cause may be specific to that destination rather than the lease.
Apple also recommends checking basic Wi-Fi connectivity and the Mac’s date and time. Renewing a lease does not sign in to a hotel portal, replace a Wi-Fi password or repair a provider outage. Record what changed and move to the next relevant check instead of repeatedly resetting unrelated settings.