MySQL (InnoDB) transactions are ACID, with A for atomicity.
An atomic transaction is an indivisible and irreducible series of database operations such that either all occur, or nothing occurs
The atomicity here is different from the atomicity in concurrent programming.
An operation acting on shared memory is atomic if it completes in a single step relative to other threads.
Suppose you want to read a number from a column, add it by an offset, and write it back to the same column.