There are many different types of bid’ah (innovation), but as a general rule, there are three main ones:
-Bid’ah Hasanah- this is a good innovation. For example, Umar (radi allahu anh) referred to the taraweeh prayer with congregation in Ramadan as a good bid’ah.
-Bidah Sayyi’ah- an evil innovation which is sinful.
-Bidah Mubah- an innovation which is neither rewarding nor does it lead to sin.
And Allah knows best!