Secure copy of files between ubuntu systems

The syntax of the command for copying a folder from directory A in system user1@ipaddress1 to home directory in user2@ipaddress2 is given below:

Sign into the system as user1 and go to directory A in which the folder to be copied resides.
Then
scp -r folder user2@ipaddress2:~

The system will ask for the passwords and a copy task will be done. Here,
          -r is option to specify that a folder needs to be copied and not a single file.
          ipaddress of the logged in system can be found using the command ifconfig
          ~ specifies that the file is to be copied to the home folder of user2.

njoy!