The term "echelon" has multiple meanings depending on the context. Here are some of the most common meanings:

• Military Formation: An echelon formation is a formation in which its units are arranged diagonally. Each unit is stationed behind and to the right (a "right echelon"), or behind and to the left, of the unit ahead. This formation is commonly used by the military, especially the infantry, to attack a set of positions.

• Intelligence Collection System: ECHELON is the name of a top-secret global network of electronic spy stations that can eavesdrop on telephones, faxes, and computers. It can even track bank accounts. This information is stored in ECHELON computers, which can keep millions of records on individuals. Officially, however, ECHELON doesnt exist. Documents leaked by the former NSA contractor Edward Snowden revealed that the ECHELON systems collection of satellite data is also referred to as FORNSAT - an abbreviation for "Foreign Satellite Collection".

• Level of Worthiness or Achievement: Echelon can also refer to a level of worthiness, achievement, or reputation. For example, "studying hard to get into one of the top echelon colleges".

• Home Exercise Equipment: Echelon is also a brand of home exercise equipment that offers live and on-demand classes, including cycling, rowing, and treadmill workouts. Echelon Premier Membership unlocks daily live classes and over 15k of a variety of on-demand classes.

In geology, "en echelon" describes an arrangement where a set of short linear features overlap or are staggered in a line that runs obliquely to the strike of the individual features. Echelon faults and en echelon veins are examples. In sheet material response to shear stress, it is typical for a series of echelon cracks to form. This is commonly seen in asphalt roads subject to shear.