What is encryption?
The process of encrypting data means to make it so that it is unreadable to anybody except the the person who is supposed to ge the data. When non-secured messages are sent over the Internet, it is virtually impossible to determine how many people may have access to the equipment being used, without physically securing the wires used to transport the message.
The next best thing to physically securing the equipment is to employ a method that makes the data useless to everyone except for the intended recipient.
Encryption uses mathematical algorithms to change a message into what appears like gibberish. If the recipient has the confidential “key” needed to “decrypt” the message, the data will be changed back from gibberish into the original message prior to encryption. The recipient will provide a password or passphrase which represents the “key”.
If someone manages to access the secured message during transmission to the recipient, it is virtually impossible for a “hacker” to decrypt the message without knowing the “key”.