What is the distinction between data in transit and data at rest?

The distinction between data in transit and data at rest primarily revolves around the state of the data and how it is being used or stored. Data in transit refers to data that is actively moving from one location to another, such as being sent over the internet or through a network. It is in motion and is not stored in a permanent location at that moment. This aspect makes it vulnerable to interception and eavesdropping, which is why encryption protocols, such as TLS/SSL, are commonly used to secure data in transit.

On the other hand, data at rest pertains to data that is stored in a permanent location or medium, such as servers, databases, or storage devices, and is not actively being transferred or processed. It is essentially resting in a state of storage but can be accessed whenever necessary.

Other options don't capture the fundamental difference correctly: data at rest is not necessarily actively being processed, so that choice misrepresents the state of data at rest. Immediate accessibility doesn't define data in transit well, as accessibility can be determined by various factors. Finally, while it's a best practice to encrypt data at rest for security, not all data at rest is always encrypted, making that statement incorrect as a defining characteristic.