Is CRUD a design architecture pattern, which can be explained in different views?
This involves history.
The term is used a lot related to the database, but also for screens that behave within the basic operations that a database usually performs.
The original term was CRUD Matrix. It referred to the operations of Creating (Create ) , reading (Read ) , updating (Update) and removing (Delete) a data in the database. And the possibility of creating a screen interface that symbolizes this for the user, generally called CRUD Screen.
Over time, people shortened it to just using CRUD and then you don't know exactly what you're talking about.
Anyway, it's a nomenclature for something that happens. It's not an architecture, it's not a traditional design pattern, although it resembles it in certain contexts because it indicates something an application does, but not in enough detail to be a design pattern , nor is it a language.
It is still a pattern of doing certain things, but not a DP, not defined as it should be.
Some people use the term CRUD Layer, so in a way it can be considered a layer, but that's weird when you consider other ways of looking at the application. CRUD can occur at multiple application layers. In an MVC CRUD has a view , a controller and a model . The important thing is that it does these 4 data access/manipulation operations (it doesn't have to be exactly a traditional database, nor does it need to be a relational DBMS, although it is quite common).
It's almost something informal as we use the term today, to indicate that you are taking care of a basic registration. Interestingly in well thought out real applications removal is not usually a necessary and correct operation. People do it without thinking because they usually just follow cake recipes.