Which TCP-related term defines the maximum packet size a host interface can accept on ingress?

MRU (Maximum Receive Unit) defines the largest packet size, including headers and data, that a network interface can accept on ingress without fragmentation. This is a local interface setting. MTU (Maximum Transmission Unit) defines the largest packet size an interface can send without fragmentation. PATH MTU refers to the smallest MTU along an entire network path, which is discovered dynamically. Window size relates to TCP flow control, indicating how much data can be sent before an acknowledgment is required, not packet size.