Ports and remasters are pretty much the same thing, only different by the time that separates them.
Many multi platform games have differences in assets, resolution, frame rate and effects. We only call them remasters when they come out a lot later than the rest.
It's the same with movies, the first batch on dvd and blu-ray are ports from the movie basically. Second time and onwards it's called a remaster. The process is the same, only technology has improved.
I wonder if Rise of the Tombraider PS4 will be sold as a remaster or a port? It will be a year later, probably with some extras and a few enhancements, If Tombraider definitive was a remaster, I guess Rise of the tombraider will be too?
Remakes: write the code from scratch and create new art assets, new dialogue etc.
I would say different versions of Tetris are remakes. Different code, different assets.
Yet the countless versions of Dragon's lair lean closer to remasters, although I doubt the code has anything in common between Laserdisc and iOS versions.
Tomb raider Anniversary Remake.
Tomb raider 2013 Prequel / Reboot
Tomb raider Guardian of light Spin-off