Ma'anar ƙamus na kalmar "gefen bashi" tana nufin gefen dama na lissafin lissafin inda aka rubuta duk ƙididdigewa ko ingantaccen shigarwar. A cikin ajiyar kuɗaɗen shiga sau biyu, kowace ma'amala ta kuɗi tana da shigarwa biyu, ɗaya a gefen zare kudi ɗaya kuma a ɓangaren kiredit. Ana amfani da ɓangaren kiredit na asusu don yin rikodin duk ma'amaloli da ke haɓaka ma'auni, kamar kudaden shiga, tallace-tallace, alluran babban jari, da sauran kadarori. Sabanin haka, ana amfani da gefen zare kudi na asusu don yin rikodin duk ma'amaloli da ke rage ma'auni, kamar kashe kuɗi, asara, da cirewa. Don haka, ɓangaren kiredit na asusu yana wakiltar ƙimar wannan asusu.