In terms of file formats, there are gulfs of differences between macs and PCs, as the macOS often uses propeitary means to generate files whereas PCs do not. Probably the most pertinent is related to object embedding in software like Office. Office embeds files differently on macs vs. every other machine. On a mac, office uses quicktime to compress and embed images. Unfortunately, it uses a very propietary form of quicktime that is only found on the mac. Hence, if you improperly imbed a picture into a presentation and then transfer said presentation to a PC, the images would not show up and the formatting may be screwed up.
Office on a PC embeds objects properly, so you cannot screw up the formatting by going from a PC to a mac.
In fact, pure text files are the only case in which it does not matter since you can encode text files as binary data on most systems. The only issue there may be bigendian vs. littleendian, but since most equipment uses littleendian(except Sun I believe), this is not an issue.