What is the difference between path.join() and path.resolve(), and when would you use each?

path.join() concatenates path segments together and normalizes the result (resolving '..' and '.' segments), but doesn't guarantee an absolute path -- if all inputs are relative, the result stays relative. path.resolve() processes segments right-to-left, treating them as if changing directories, and always returns an absolute path, using the current working directory as the base if no absolute segment is encountered -- resolve() is typically used when you specifically need a guaranteed absolute path, while join() is used simply to combine path pieces correctly regardless of whether the result ends up absolute or relative.

const path = require('node:path');

path.join('users', 'alice', 'file.txt'); // 'users/alice/file.txt' -- relative, as given
path.resolve('users', 'alice', 'file.txt'); // '/current/working/dir/users/alice/file.txt' -- always absolute