Interconnected networks that transmit data between and across countries and continents.

Middle Mile The electronics and circuitry that carry a signal from interconnection points and aggregation facilities to a Central Office or Point of Presence. 

Last Mile The electronics and circuitry that deliver the Internet service to a household.

*Point of Presence(POP): Demarcation point, access point, or physical location at which two or more networks or communication devices share a connection. 

**Example of Middle Mile Aggregation Facility is An Internet Exchange Point (IXP), which is a physical location through which Internet infrastructure companies such as ISPs connect with each other.

 ***Example of Middle Mile Interconnect Facility is a Data Center, which is a facility responsible for driving Internet content delivery and managing network resources.

source : https://broadbandusa.ntia.doc.gov/sites/default/files/2022-12/Introduction_to_Broadband_and_High_Speed_Internet_FINAL_0.pdf