The fact of being at different/same colleges or different/same universities has zero bearing on whether it is considered plagiarism or not.

If you submit a project that includes someone else's work, without making it clear what is your own work and what is not (and crediting the other contributor/s properly), this is plagiarism. This is true whether the other contributor is at the same college, same university, someone not in college at all, etc...

I'll assume that you worked together on the project, rather than just completely independently coming to the same place. That seems to be what you mean.

If you work on the project together and acknowledge the joint work then it probably isn't technically plagiarism. But it will almost certainly be considered as academic misconduct if you submit the same work to two different courses unless you make the faculty aware and get permission.

Note that you (a) have to list both authors on it and (b) get specific permission.

Whether it is permitted by the faculty or not is up to them. If the work is significant enough (more than one person is expected to do) then you have a better chance of getting accepted.

But if you submit two papers, identical, but each listing only one author, then it would be plagiarism. And also, separately, academic misconduct, but of a higher order.

Yes, it's still plagiarism.

If Assignment 2 for your class ABC321 at your college is the same as Assignment 5 of class DEF234 at a different one, submitting a copy of the solutions manual for DEF234 to your professor at your college as being your own work is considered cheating even if it came from another college.

If your friend and you receive the same assignment for different classes and you decide to split the work and copy off each other it's not different than the scenario stated above: it's plagiarism.

It doesn't matter who you copied from (solutions manual from a previous year or directly from your friend) or what the thing you copied was originally (submission for ABC321 or DEF234). Plagiarism is plagiarism.

Plagiarism depends on copying, not similarity or location.

If one of you copied the other's work, then it's plagiarism. Doesn't matter where or when or how.

I suspect what you're actually asking is not whether it's considered to be plagiarism when you copy someone's work (because of course it is), but whether that plagiarism will be noticed by your respective colleges. If you're on separate campuses then the probability of this is likely quite low. Work submitted on paper will most likely be assessed by the teachers at each college, so the fact that there are two identical papers at different colleges is unlikely to be spotted. If the results are submitted electronically though, the fact of the two colleges being part of the same university may get you caught if there's a university-wide check on duplicate work being handed in. Or for bonus irony points, if the work is particularly good then it's possible that one teacher may show it to the other as a golden example, at which point of course the other teacher will remember they've just seen something remarkably similar.

I was a teaching assistant for computer science at the University of Kentucky (UK). I can almost guarantee you that at UK any kind of paper is always run through a plagiarism checker that is linked to many other universities and colleges that checks for (among other things) percent of difference, if another assignment has been found to have too low a percent of difference then it will flag the assignment as plagiarism and will give a report to the professor so that they can see the one that was already in the system and the one that you just submitted and compare for themselves.

If you mean, you and this other person both created these project independently and by sheer coincidence they just happen to be word-for-word identical, that's not plagiarism, that's a miracle.

If you mean that you copied your friend's work and intend to submit it as your own, that's pretty much the definition of plagiarism. The fact that you're at a different school does not in any way make it not plagiarism. If you copy somebody else's work and say or imply that it is your own, that's plagiarism, and whether the work was created on a different continent by someone you never met, or by your room mate, is irrelevant.

If the two of you worked on this project together, and now you are each planning to hand it in at your own school, then if you acknowledge the other person's contribution it is not plagiarism. It may or may not satisfy the requirements of the assignment. If you were supposed to do the work yourself, then getting a friend to do part of the work does not meet the requirements of the assignment.

Plagiarism is misrepresenting something as your own original work when it is not. If you are doing this, it is plagiarism. If you are not doing this, it is not plagiarism.

If two people miraculously independently writ precisely the same paper, even word for word, that is not plagiarism. Each person has the absolute right to represent the paper as their own original work because it is. However, if two people collaborate on a work and each submits it independently as their own work, that is plagiarism. Neither person can honestly represent that the paper is their own original work.