Transport Layer Security (TLS):

• Purpose: TLS is primarily used to provide secure communication over the internet. It ensures that the data exchanged between a user's device and the server remains private and secure.

• Functionality: TLS encrypts the data transmitted over a network, preventing eavesdropping and tampering by third parties. It's widely used in web browsing (HTTPS), email, VoIP (Voice over Internet Protocol), and other applications that require secure data exchange.

• Authentication and Encryption: TLS involves authentication (verifying the identities of the communicating parties), encryption (encoding the data to protect it from unauthorized access), and integrity (ensuring the data is not altered during transmission).

• Versions: TLS has evolved over time, with TLS 1.3 being the latest version, offering enhanced security and performance.
  

Secure Real-time Transport Protocol (SRTP):

• Purpose: SRTP is designed for securing real-time communication protocols, primarily voice and video calls made over IP networks.

• Functionality: It provides encryption, message authentication, and integrity for data in real-time applications. This is crucial for applications like video conferencing and VoIP, where sensitive information is often shared.

• Real-time Communication Security: Unlike TLS, which is more general-purpose, SRTP is optimized for the real-time nature of voice and video, ensuring minimal delay and overhead.

• Integration with Other Protocols: SRTP is often used in conjunction with other signaling protocols like SIP (Session Initiation Protocol) for initiating and managing secure voice and video communication sessions.
  

Both TLS and SRTP are essential for maintaining the security and integrity of data in their respective domains of application — TLS for general secure communication over the internet and SRTP for protecting real-time voice and video transmissions.