前缀 intra- 与 inter- 往往造成混淆。尽管两者的拼法、发音及用法非常相似，但事实上它们表达的意思几乎完全相反：intra- 的意思是“在…之内（inside 或 within）”，而 inter- 的意思则是“在…之间（between 或 among）”。以下是这两个前缀的代表性用法。
intercontinental: between continents
interdepartmental: between or among departments
interdisciplinary: involving multiple disciplines
interaction: reciprocal influence between
interplanetary: between or among planets
intracellular: inside a cell
intradepartmental: within a department
intravenous: within or into a vein
intrauterine: inside a uterus
intramural: within a school