Through the CheckSum or checksum function you can quickly and easily verify that the address you are using is correct. Or if, on the contrary, it is altered in any way. Avoiding unconsciously sending your cryptocurrencies to a false, incorrect or non-existent address.
Although, in theory, it would be impossible to send bitcoins to an address that does not exist or that is written incorrectly. Because these addresses, when generated, incorporate a checksum code. This data represents the hash value of the address and the data of the sum make up an own alphanumeric scheme known as Base58Check.
This saves the checksum directly within the address. And thus, if an address is entered incorrectly, the checksums of both addresses do not match. In this way, the wallet prevents a transaction from being made when addresses are entered incorrectly.
In Bitcoin the hash function SHA-256 it is applied twice to generate a 32-byte hash, where the first 4 bytes (32-bit) are taken as the checksum to detect typos in the addresses. And, although through this verification sum the keys associated with the address cannot be obtained, if it allows the verification of said keys. Thus, it is possible to avoid making an error when making a transaction.
This simple procedure ensures that you cannot go wrong when entering a Bitcoin address. In fact, the probability that you are wrong is 1 in 4.294.967.295.