What kind of addresses are used at the Internet Layer?

At the Internet Layer, IP addresses are used for identifying devices on a network and facilitating communication between them. The Internet Protocol (IP) is responsible for routing packets of data from the source host to the destination host based on these addresses. IP addresses can be either IPv4 or IPv6 and provide a unique identifier for each device on a network, ensuring that data is sent to the correct location.

MAC addresses, on the other hand, function at the Data Link Layer and are used for local network communication within a single network segment, rather than across the broader internet. Domain names are a higher-level abstraction that resolves to IP addresses but are not used directly at the Internet Layer. HTTP headers relate to the application layer protocols and are used primarily for web communication, not for routing data at the Internet Layer. Thus, IP addresses are the correct choice for this question regarding the Internet Layer.