Ma'anar ƙamus na kalmar "concurrency" ita ce gaskiyar al'amura biyu ko fiye da haka da suka faru ko suke faruwa a lokaci guda, sau da yawa kan haifar da wani yanayi inda suke mu'amala da juna ko tasiri. > A kimiyyar kwamfuta, haɗin kai yana nufin ikon tsarin kwamfuta ko shirin aiwatar da ayyuka da yawa ko matakai a lokaci ɗaya, ko sarrafa masu amfani da yawa don samun damar hanyar haɗin gwiwa a lokaci guda. Ana samun wannan sau da yawa ta hanyar amfani da zaren zare, matakai, ko wasu dabaru na shirye-shirye iri ɗaya.