传统的轻装步兵（英语：light infantry），又称散兵（英语：skirmishers）士兵，他们的工作是提供步兵主力一个先遣的遭遇战，骚扰和拖延敌人前进。轻装步兵，与步兵、重装步兵或线列步兵是不同的。重装步兵，主要致力于在致密阵形，分别为核心的大型战役战斗。轻装步兵与重装步兵经常转战密切协调，在那里他们可以筛选重装步兵的骚扰火力；重装步兵则攻击敌人的重装步兵或骑兵，可以进行干预，以保护轻装步兵。重装步兵原本比轻装步兵有较重的武器和盔甲，但这种区别是失去使用装甲下降与否，和火药武器变得标准化。

Light infantry (or skirmishers) are soldiers whose job was to provide a skirmishing screen ahead of the main body of infantry, harassing and delaying the enemy advance. Light infantry was distinct from medium, heavy or line infantry. Heavy infantry were dedicated primarily to fighting in tight formations that were the core of large battles. Light infantry fought in open-order, often in close co-ordination with heavy infantry, where they could screen the heavy infantry from harassing fire, and the heavy infantry could intervene to protect the light infantry from attacks of enemy heavy infantry or cavalry. Heavy infantry originally had heavier arms and more armour than light infantry, but this distinction was lost as the use of armour declined and gunpowder weapons became standardized.