At its most basic function, a herotag allows associating complex pieces of information, such as a wallet address, to a human-readable name. This means that instead of sending money to erd1hmlnypa0c9x7canxgdsue86ckla0zekv0258f2q40ady50v8yxc92y5k2y you can just send it to @alicejohnson.
Note: Crypto transactions take place on public blockchains. Your herotag is public and advanced users can look up your address on the blockchain and view your transactions history. Turning visibility OFF (from Profile Info screen) will make your herotag private only inside the xPortal app, but not on the blockchain.
Once you have claimed your @herotag you cannot change it.
Because the herotag is using the Distributed Name Service and it is saved on the blockchain, changing the herotag associated with a MultiversX address is not possible.
We are researching the possibility to add more options in the future: add aliases, transfer herotag, etc.