Socket address is:

Question

Socket address is:

Accepted Answer

The correct option is (2):

The socket address is formally defined in networking as the **Combination of IP address and port address**. A socket acts as an endpoint for communication between two programs running over a network, and to establish this communication, the system needs to uniquely identify both the host computer and the specific application process on that host. The **IP address** serves to locate the unique computer on the Internet (Network Layer), while the **port address** (a 16-bit number) serves to identify the specific application or service running on that machine (Transport Layer). Together, this IP address and port number pair forms the unique socket address, allowing protocols like TCP and UDP to ensure data is correctly delivered to the intended recipient process.

The incorrect option is (1):
**IPv4 address translated to IPv6 address** is a process related to network transition or compatibility, typically handled by mechanisms like Network Address Translation (NAT) or tunneling, to allow hosts running different versions of the Internet Protocol to communicate. This is a technical conversion method, not the definition of a socket address itself. A socket address uses *either* an IPv4 address *or* an IPv6 address, combined with a port number, to define the endpoint.

The incorrect option is (3):
The **Combination of MAC address and domain address** does not constitute a socket address. The MAC (Media Access Control) address is a physical, Layer 2 address used for local communication within a single network segment, not for end-to-end communication across the Internet. Furthermore, a domain address (like `example.com`) is an abstract, human-readable name that must first be translated into an IP address using DNS before a socket connection can even be initiated.

The incorrect option is (4):
The **Application layer address** is too vague a term to define the socket structure. The socket is fundamentally a concept that operates at the Transport Layer (Layer 4) and Network Layer (Layer 3) interface. While the Application layer (Layer 7) uses the socket for sending and receiving data, its own address is merely the destination IP address and port number that form the socket address, making this option an incomplete or imprecise description.