Front line and Line of battle

Front line noun - The leading or most important part of a movement.

Line of battle and front line are semantically related. In some cases you can replace phrase "Line of battle" with "Front line", this phrases are similar.

Line of battle noun - A line formed by troops or ships prepared to deliver or receive an attack.

Front line and line of battle are semantically related. Sometimes you can replace phrase "Front line" with "Line of battle", this phrases are similar.