What are the three permissions available on posix file systems?

https://documentation.suse.com/sles/12-SP4/html/SLES-all/cha-security-acls.html

The three permissions available on posix file systems are read, write, and execute. The read permission allows the user to view the contents of a file or directory. The write permission allows the user to modify or delete a file or directory. The execute permission allows the user to run a file as a program or change into a directory. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-file-permissions.html#sec-file-permissions-types