Glossary · Wallets
Delegation.
Pointing your stake at a specific stake pool so it can produce blocks on your behalf.
In depth
Delegating does not move your ada anywhere; it only declares which stake pool may count your balance toward its block production chances. Delegation is registered with a certificate signed by your staking key and stays in effect until you change it.
Example
You publish a delegation certificate naming pool TICKER; two epoch boundaries later your ada starts strengthening that pool's block-production odds, and rewards land roughly four epochs after the certificate.