Toggle read, write and execute for owner, group and others, and the tool shows the matching octal (e.g. 755) and symbolic (rwxr-xr-x) representations to copy.
Owner has read, write and execute (7); group and others have read and execute (5). It is common for scripts and directories.
Each permission class sums read=4, write=2 and execute=1, so rw- is 6 and r-x is 5, giving three digits like 644 or 755.
644 grants execute to no one (typical for regular files); 755 adds execute for everyone, needed for scripts and directories.