Account Abstraction as defined by ERC-4337, "allows users to use smart contract wallets containing arbitrary verification logic instead of EOAs as their primary account." ERC-4337 introduces many user experience benefits, most notably enabling people to use Smart Contracts as their primary accounts.
Here is a quick explanation:


As a developer, you gain the following benefits:
  1. 1.
    Easily sponsor's your user's transaction.
  2. 2.
    Batch multiple actions insto single tx. Example, Uniswap requires first approval pool and then another for actual swap. With Account abstraction, both of them is just 1 transaction.
  3. 3.
    Allow users to pay in different ERC20 tokens.
  4. 4.
    Login/Logout users, sign messages without them having to deploy smart wallet.
If you are interested to learn more about them, here are useful references: