The type of address used at the Transport layer to identify the receiving application is known as the "port number".
At the Transport layer, the receiving application is identified using the Port address. Port addresses are used in conjunction with IP addresses to ensure that the correct application on the receiving device receives the incoming data. Port numbers range from 0 to 65535, with well-known port numbers assigned to specific applications or services (e.g., Port 80 for HTTP, Port 443 for HTTPS).
