Paradox

Definition
A paradox, in time manipulation, is a loop that will keep being different from the last evaluation each time it is re-evaluated by time.

Time Travel
Paradoxes can be caused by a multitude of things, however, one of the most famous time travel paradoxes is the "Prevent yourself from time travelling" paradox.

In this paradox, you have a time machine, go back in time, and a change you make intentionally or unintentionally prevents your past self from time travelling. It you CAN actually make this paradox while still allowing your past self to time travel, but removing the reason for removing the reason.

Some paradoxes could be more subtle, and harder to notice that they would occur. However, all time travel paradoxes stem from a time traveler changing an event in the past which then, in turn, changes the time traveler into doing something else.

Time Manipulation
While Time Travel paradoxes may stem from that, Time Manipulation paradoxes don't necessarily follow that rule.

Time Manipulation paradoxes are even easier to create than Time Travel paradoxes. In order to create a time manipulation paradox, two things have to be going in opposite directions through time. If they are going in the same direction, even at different speeds through time in that direction, a paradox will not occur.

If they are just two boxes that collided in opposite directions through time, a paradox will not occur.

An example of a time manipulation paradox would be two people going in opposite directions through time having a conversation.