This question already has an answer here:
Using the Mac terminal whenever I hit enter, regardless of shell it outputs the line with square brackets. The issue doesn't occur in iTerm2.
Dan@Mac ~ [10:32:55] [> $ ] Dan@Mac ~ [10:36:11] [> $ ] Dan@Mac ~ [10:36:11] > $
So above is what there term looks like, input goes at > $ however on enter it shows with [> $.
Any advice appreciated, let me know if you need any other details.
edit: To clarify as this was marked duplicate of another thread which asks the functionality/purpose of mark, when posting this I did not know what mark was or that it existed.