Why does the space optimization problem occurs in any android phone.

Hello dosto mene is video me aapko bataya he, phone ke space cleaning problem ke baare me or aapka phone hang kyu hota he. Ise mene teen points me samjhane ka prayas kiya he,to friends please video ko pura dekhna or video ko like or share Karna and the most important thing is that friend's please complete my first 1000 subscribers on YouTube, taki me or bhi apke liye achi se achi faydemand videos lata Rahu, so keep supporting.................. The space cleaner apps link..

How can we solve Storage problem of any phone and why does our phone hang.,