Extensions in D365FO

Dear All,

Can you please let me know if we are going to work with Standard Objects on Table, View, Queries and Data Entities. So, we need to work with Extensions.

I saw for each Objects we have extension. Like Table. extension, View.extension etc...

For example :

If i need to work with Standard View. So,create my own view.extension to work OR we can work directly with objects under View.extensions?

Please give me more shed on this.

Thanks!