A time paradox is simply something that causes an infinate loop in the humans concept of time.
For example, if Human A went back in time, married his great grandmother, and concieved babies with her, this would be a paradox in a multitude of ways.
There are two things that could then occur, the branching time theory, or the singular time theory. The branch theory determines that when he returns to his future, it is in fact intact as if nothing happened. Instead, this event created two dimensions, one is the dimension wherein he changed history, and was never born due to this. Thus, this event never occured.
The second dimension is the one he is currently in, unaltered by his time-traveling escapades. This theory makes it so that it is impossible to alter your own past, as it will always be the same. You will simply be creating an alternate dimension.
The second theory, the single timeline theory, instead proves that by doing so, he eliminated himself from his time period. Soon after the changed events, Human A vanishes due to having never existed. However, this creates a paradox, since he never existed, he never had a chance to go back in time to do so, creating a paradox. This kind of paradox can never be broken, and instead eliminates said family from the entire timeline. Of course, all of this is detailed in my one million, three hundred fifty four thousand five hundred and ten paragraph file on the concept of paradoxes, and how one can cause and stop them.
Please continue to data +1AX for the first five hundred paragraphs.