What is data encryption used for?

Ans: Many data thieves do their work without breaking into computers systems, they intercept message as they travel between computers on networks. Passwords are of little use for hiding electronic mail messages when they are travelling through phone lines or internet gateways still scientific in the name of security. Many networks secure while allowing communication with the rest of the internet. The technical dtails of firwalls vary considerably, but they are all designed  to serve the same function to ground against and unauthorized access to an internal network. In effect, a firewall is a gateway with a lock- the lock gate is opened only for information packets that pass one or more security inspections.