There are 3 main types of remote operation that you will find useful in scientific computing with linux:
- logging in to remote machines - known as ssh
- copying files between your machine and a remote machine - known as scp
- file transfer between your machine and a remote mahcine - known as sftp
All three of these applications make use of the Secure SHell. In the past (before secure shell), remote operations carried many more security risks than is the case today. Most linux distributions run an open-source version called OpenSSH. The secure shell provides an encrypted communications between untrusted computers over an untrusted network.
Follow the links above to find out about each type of operation.