Final answer:
Port 443 is commonly associated with HTTPS, which secures communication over networks, frequently on the Internet. It ensures the integrity and confidentiality of data using encryption with TLS or SSL, particularly important for sensitive transactions.
Step-by-step explanation:
Port 443 is associated with the commonly used protocol known as HTTPS, which stands for HyperText Transfer Protocol Secure. This protocol is an extension of HTTP and is used to provide secure communication over a computer network, and is widely used on the Internet. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS), or formerly, its predecessor, Secure Sockets Layer (SSL). The primary function of HTTPS is to protect the integrity and confidentiality of data as it is transferred between the web server and the user's browser.
Unlike HTTP which operates over port 80, HTTPS typically uses port 443 to provide a secure channel over which data can be sent securely. This secure protocol is essential for online transactions, such as banking, shopping, and any situation where sensitive information, such as personal details or credit card numbers, is exchanged.