Ma'anar ƙamus na kalmar "gabon jini" yana nufin kwayar halitta ko barbashi da ke cikin jini. Akwai manyan nau'ikan gawar jini guda biyu: Jajayen Kwayoyin jini (wanda kuma aka sani da erythrocytes) da farin jini (wanda kuma aka sani da leukocytes). Kwayoyin jajayen jini ne ke da alhakin daukar iskar oxygen daga huhu zuwa sauran sassan jiki, yayin da fararen jini ke cikin tsarin garkuwar jiki da kuma taimakawa wajen yakar cututtuka da cututtuka. Duk nau'ikan gawar jini suna da mahimmanci don kiyaye lafiyar gaba ɗaya da walwala.