What is the primary function of Internet Protocol (IP)?

The primary function of Internet Protocol (IP) is to facilitate the transfer of data packets across networks. This core responsibility allows IP to define the rules for addressing and routing data so that it reaches its intended destination over a diverse set of networks. IP operates at the network layer of the Internet Protocol Suite, ensuring that data is broken into packets, which are then sent individually across various routing paths in the network. Each packet contains not only the payload of data but also the necessary header information, including source and destination IP addresses. This process ensures reliable communication between devices on different networks.

Other options, while related to internet functionality, do not accurately describe IP's primary role. Securing internet communications falls under protocols such as SSL/TLS, which focus on encryption rather than packet transfer. Email services are managed by protocols like SMTP, POP3, or IMAP. Connecting devices to the internet generally involves hardware and network configurations rather than the specific transmission responsibilities of the IP protocol itself.