The command key on Mac is equivalent to the control key on windows. However, there are some programs that use the control and not the command key.

The same command on a mac would be command key(cmd)+A

any ctrl key command is the same as the cmd key on a mac

The nearest equivalent Meta key to a Mac's Command key on a Windows PC would be the Windows key although many of the Commands that use the Control key (on Windows) are performed with the Command key on the Mac.

b

Go to the Command prompt and run "help" command to see the command list..