Information transferred via the Internet might go through many different networks and equipment during its journey until reaching the recipient. In such a case, the information becomes vulnerable to being intercepted and read or modified by a third party. Encrypting makes it impossible by converting plain-text information into cipher text that can only be deciphered by using an encryption key.

One of the technologies that help to protect information from being intercepted is Transport Layer Security (TLS). This technology is used by HTTPS protocol that helps to protect communication between the browser and website. With TLS, the client and server perform a handshake and negotiate their security parameters and encryption keys that are then used for encrypting the information transferred.  

That means that intercepting encrypted information does not allow to see the original message.

Encryption is just one component of TLS. Another essential element for a secure connection would be authentication and integrity.

Authentication will help the browser recognize that it communicates with the right server. Normally websites employ digital certificates that will link the identity of the website with its public key, which will allow the browser to identify the server in TLS connection.

Another key element is integrity. The system must not only protect the information from being read but detect if someone tries to change the information secretly. Integrity will be protected along with encryption in TLS. 

Modern TLS connections use known cryptographic algorithms and not simply hide text using substitution. The latest version of TLS is TLS 1.3 according to TLS protocol, while older version is TLS 1.2. SSL technology has been superseded by TLS.

Thus, when you see HTTPS in your browser, then encryption is performed as part of TLS security.

It is necessary to clarify what this protection entails and doesn’t entail.

The protection of data takes place in the process of its movement from one endpoint to another. It is typically considered as providing data in transit security. For instance, when a user sends information to some website via HTTPS, TLS ensures protection during the process of information’s travel. 

TLS doesn’t provide automatic protection that prevents any entity from accessing data. The data can be decrypted by the endpoint – in our case, the server of the website. If information is stored further, then other protection techniques should be used to secure it at rest. 

The end-to-end encryption technique works differently. Under the conditions of an end-to-end encryption communication, the message gets encrypted in such a way that only intended endpoints are supposed to decrypt it. That means that the service which operates the network can’t read the message in its plain text.

In simple words:

Encryption provides confidentiality, authentication checks the identity of your communication partner, and integrity prevents tampering.

All these technologies make modern internet communication much safer compared to unprotected communication over the internet.