What is it?
Supplying means depositing a token into an Aave pool so other people can borrow it. The supplier keeps a growing balance and can usually withdraw later, subject to available cash in the pool.
Why does it matter?
Supply size tells you how much of an asset Aave is holding. Big supply with little borrowing often means lots of spare cash. Big supply with lots of borrowing means the asset is in demand.
Example
Maya supplies 10,000 USDC on Aave Ethereum. The pool can now lend that USDC. Maya's aUSDC balance starts at 10,000 and slowly increases as borrowers pay interest.
Where can I find it?
Live Activity filter Supply. Asset pages show Supplied. Overview shows Supply volume in window for recent supplies in the current log window, not all-time.