Maximum transmission unit (MTU) is the largest size of a data block that can be transmitted without fragmentation.
The larger MTU, the less overhead. Decrease of MTU leads to a reduction of network latency. MTU depends on basic network abilities.
For this purpose the Maximum transmission unit parameters can be adjusted manually or automatically.
MTU is used in communication protocols and network layers. There are certain standards (Ethernet and others) that specify the MTU size. Also some systems can determine the MTU at the time of connection. The link layer and the physical layer usually add an Overhead to the data being transmitted.
Increasing the MTU increases efficiency because each network packet can carry more user data at a fixed Overhead. This requires processing fewer packets for the same amount of data. However, larger packets take longer on the link than smaller packets. This causes next packets to be delayed and increases network latency.