While I was working on 日本語総まとめ N3 文法, I came across the following.
ここの砂は星みたいな形をしている.
Now I know that this translates to "The sand here in this area are star-shaped."
What I don't understand here is the usage of the bold-faced phrase をしている. Can someone please help me with this? Problem is the usage (in what sort of occasions specifically).