See backhaul in Computer
The original definition of backhaul was to transmit a telephone call or data beyond its normal destination point and then back again in order to utilize available personnel (operators, agents, etc.) or network equipment not available at the destination location. For example, depending on distances and service arrangements, it might be cheaper to send a telephone call on a private line to a location way beyond the destination and then dial up the destination, which is back in the other direction.
The term evolved into a more generic meaning and often refers to transmitting from a remote site or network to a central or main site. It implies a high-capacity line; for example, to backhaul from a wireless mesh network to the wired network means aggregating all the traffic on the wireless mesh over one or more high-speed lines to a private network or the Internet.
Learn more about backhaul