两单词均有“宣誓作证者”的含义，且有时两个单词可以互换使用，但两者仍有一定差异。区别在于前者为自愿提供有关事实之宣誓书（affidavit)者[1];而后者指对在质询和诘问下提供口供宣誓书（deposition)者[2]。

[1 ]“Affiant is the person who makes and subscribes an affidavit. The word is used, in this sense, interchangeably with deponent. But the latter term should be reserved as the designation of one who makes a deposition. " Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 36，West Publishing Co. (1991 ).
[2 ]“A person who gives a deposition. ” Cf. Linda Picard Wood, J. D.，Merriam Webster's Dictionary of Law, at p. 133, Merriam-Webster，Incorporated (1996 ).