A sleeve is the part of a garment that covers the arm, or through which the arm passes or slips.
Actress Mabel Love in an outfit with leg-o'-mutton (gigot) sleeves in the 1890s.
Image: Japon van donkerblauwe ottoman ripszijde met wijd rokdeel met dubbele plooien, brede ronde kraag en dubbele rij knopen, “Cargelli”, objectnr 61941
Image: Batwing sleeve
Image: Bishops sleeve
A shirt is a cloth garment for the upper body.
Charvet shirt from the 1930s, Norsk Folkemuseum, Oslo, Norway
Factory sewing
Shirts on a conveyor
Shirts awaiting finishing