Stars are born from collapsing clouds of gas and dust. While the clouds are collapsing
and before nuclear fusion is initiated, the forming star is called a protostar.
Initially these forming stars are hidden inside a cocoon of
leftover dust; eventually they blow this dust away and become visible from the outside. In their early
stages the surrounding
gas and dust may form an accretion ring around the forming star
and the infalling material may be
ejected in strong winds directed along the polar axes.