File (formation) in the context of Troops

In military terminology, a column is a tactical formation of fighters moving together in one or more files in which the file is significantly longer than the width of ranks in the formation. The column formation allows the unit rapid movement and a very effective charge (due to weight of numbers), and it can quickly form square to resist cavalry attacks, but by its nature only a fraction of its muskets are able to open fire.

The line formation offers a substantially larger musket frontage than the column, allowing for greater shooting capability, but requires extensive training to allow the unit to move over ground as one while retaining the line. It is also applied by modern armies to vehicles, troops and naval vessels.

In the United States, lockstep marching or simply lockstep is marching in a very close single file in such a way that the leg of each person in the file moves in the same way and at the same time as the corresponding leg of the person immediately in front of him, so that their legs stay very close all the time.