~ (tide symbol) stand for home directory, this will be different depends on the current user of the current shell. For example on Linux if I logged in as userA, ~ will stand for /home/userA.
So any ~/myfolder is equivalent to /home/userA/myfolder, cd ~ will be equivalent to cd /home/userA.
For macOS the home folder path is /Users/<username>.
Please make sure you are comfortable with using ~ when change directory, remember the full home path name is very cumbersome. Any developer worth their pay need to optimize their workflow.