a) date prints the number of seconds since UNIX epoch
b) who shows which users are logged in
c) whoami shows the current user
d) who am i does nothing
e) pwd prints the current directory
f) cd changes the working directory
g) mkdir creates a new directory
h) rmdir removes a directory
i) rm removes a file or a directory and its contents with the -r flag
j) cp copies a file
k) mv moves a file
l) ls lists the files in a directory (with permissions)
m) cat concatenates a file or stream
n) more outputs a file to the terminal with the option to scroll
o) less does the same as more but starts at the end of the file