兩者均與債或義務(wù)的履行相關(guān)。actual performance為“實(shí)際履行”，為債的履行原則之一，指債的雙方當(dāng)事人應(yīng)當(dāng)按債所規(guī)定的標(biāo)的履行，不能由其他標(biāo)的代替履行，也不可折合成金錢代償。special performance (也稱為specific relief)主要用于合同事項(xiàng)，指由法院簽發(fā)命令，強(qiáng)制某人按其允諾履行某合同義務(wù), 因其極具強(qiáng)制性，故為“強(qiáng)制履行”，須注意的是該術(shù)語經(jīng)常被人混淆成actual performance而譯為“實(shí)際履行”。
 
“ Special performance: A court-ordered remedy that requires precise fulfillment of a legal or contractual obligation when monetary damages are inappropriate or inadequate, as when the sale of real estate or a rare article is involved. ” Cf. Bryan A. Gamer, Black's Law Dictionary, 7th edition, at p. 1407, West Group (1999).