Umshini idivayisi ehlanganiswe ezingxenyeni ezingasebenza futhi isetshenziselwe ukufaka esikhundleni somsebenzi womuntu, ukuguqula amandla, noma ukukhiqiza umsebenzi owusizo. Umshini ngokuvamile uqukethe iyunithi yamandla, iyunithi yokudlulisela, iyunithi yokusayinda, neyunithi yokulawula.
Ngokombono wamandla, umshini uyithuluzi elisebenzisa noma eliguqula amandla emishini. Amadivayisi aguqula ezinye izinhlobo zamandla zibe amandla emishini abizwa ngokuthi ama-prime movers, njengezinjini ezivuthayo zangaphakathi, izinjini zesitimu, namamotho kagesi. Amadivayisi asebenzisa amandla emishini ukwenza umsebenzi owusizo abizwa ngemishini yokusebenza, njengamathuluzi omshini ahlukahlukene, okhreni, nama-compressor. Ngokuthuthuka kwesayensi nobuchwepheshe, umqondo womshini uhlale uvuselelwa futhi ushintshwa.
