Parovoz, lokomotive, ki muharriki on moshini bugi meboshad. Elementhoi asosii Parovoz inhoand: degi bug, moshini bugi, qismi ekipaj. Zakhirahoi suzishvori, ob va ravganhoi molidaniro odatan dar tender, ki ba Parovoz qush ast, choygir mekunand. Hangami dar otashdoni degi bug sukhtani suzishvori (angisht, mazut, chub, va gyra) obi deg bug meshavad.
Moshini bugi energiyai garmiro ba energiyai mekhanikii harakati porsheni silindrhoi degi bug tabdil medihad; in harakat tavassuti mekhakizmi shatuniyu krivoshini ba charkhhoi baranda doda meshavad. Parvozhoi avvalin dar Britaniyai Kabir soli 1803 (R. Trevitik) va 1814 (J. Stefensov) sokhta shudaand (rasmi 1).
Dar Rossiya avvalin Parovozro padaru pisar B. A. va M. E. Cherepanovho (1833) sokhtaand (rasmi 2). Parovozho ziyoda az 100 sol mamul budand va faqat solhoi 50 asri 20 joi onhoro elektrovoz va teplovozho giriftand. Sababi asosii bo lokamotivhoi digar ivaz karda shudani Parovoz khurd budani k. a. m.-i on (k. a. m.-i behtarin Parovozho az 9% ziyod nest) meboshad.