三個單詞均有邊界的含義。相比較，border強調(diào)地區(qū)分界， 多含有邊境特征，如河流或山川，其含義粗略，沒有boundary 所指的精確，且由于河流或山川的改變border也可能發(fā)生變化[1]，如：cross the border into Canada。而 boundary 則多指領(lǐng)土所能達到的最遠之疆界劃分，其相當精確，可經(jīng)條約在文件或地圖上進行修改，常強調(diào)一種理論上的分界[2], 如 By international agreement，the boundary of each nation fronting a body of water extends exactly three miles from the coastline。frontier 為一國際法術(shù)語，常指兩國邊界，指某國沿著另一國border那部分的領(lǐng)土區(qū)域，因此可以說它是從一種內(nèi)部的角度去理解和看待border, 包括了比作為“邊界線”的boundary更廣泛的區(qū)域[3]。
    
[1] "Border often suggests a territorial feature，such as a river or mountain range, and hence is not as precise as boundary. ”Cf. The Editors of The Reader's Digest, Use the Right Word, at p. 61, The Readers Digest Association Proprietary Ltd. (1971).
[2]“A theoretical line that marks the limit of an area of land. " Cf. Linda Picard Wood, J. D. Meniam Webster's Dictionary of Law f at p. 58, Meniam-Webster, Incorporated Springfield, Massachusetts (1996).
[3]“In international law, that portion of the territory of any country which lies close a- long the border line of another country，and so fronts or faces it. The term means something more than the boundary line itself, and includes a tract of strip of country, of indefinite extent, contiguous to the line. ”Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 461 , West Publishing Co. (1991 ).