The yank command yanks (copies) selected text into the register x.
The put command pastes the text from register x after a specified line.
Copies text from the line 1 to line 10 into the register a.
Copies text from the line 1 to line 10 into the unnamed register.
Puts the text from register a after line 23.
Puts the text in the unnamed register after line 23.
Displaying the contents of registers
Display the register list with :reg.