This includes
all forms of cooking and baking. Even boiling water falls
under this category.
It also
includes any form of heat treatment of non-foods. Melting metal or
wax and firing ceramics are all included.
The
prohibition against cooking does not prevent us from eating hot
food on the Shabbat. Part the Sabbath joy (Oneg Shabbat) consists
of eating hot food. However, this must be prepared in such a
manner that no act of cooking actually takes place on the Sabbath.
