Java Transaction API, aka JTA, is like playing with blocks, but with a strict set of rules. Imagine you're building a tower out of blocks, but every time you add a block to the tower, you have to ask the grown-up (JTA) if it's okay.
JTA helps you make sure that multiple things happen together and that everything goes back to normal if something goes wrong.
So, let's say your tower has different levels, and you want to move a block from one level to another. JTA makes sure that it happens together with other things you might be doing, like putting a new block on a different level. This is known as a transaction, and just like with blocks, all the changes you make in a transaction happen together or not at all, so if something goes wrong, JTA helps roll everything back, so no blocks are left out of place.
JTA helps you play with blocks, I mean, code safer, so you don't accidentally break something and can make sure that everything happens together, and it can be undone if needed.