Understanding of predicate

what is predicate? ( Note: The following excerpt from the C # technical documentation)

Summary: Represents a method that defines a set of conditions and determines whether the specified object conforms to those conditions.

Public delegate bool Predicate<in t> (T obj).

Parameter: obj: The object to be compared by the criteria defined in the method represented by this delegate.

Type parameter: T: The type of object to compare.
Returns the result: true if obj conforms to the condition defined in the method represented by this delegate;

It's not easy to understand, just look at an example:

           list<string> list = new list<string> ();             List. AddRange (new string[] {"ASP. NET course, "EE course", "PHP Course", "Data Structure Course"});             predicate<string> findpredicate = new predicate<string> (isbookcategory);             list<string> bookcategory = list. FindAll (findpredicate);                                                

           static bool Isbookcategory (String str)             {                return str. EndsWith ("course")? True:false;             }  

Personal Understanding:

The role of the predicate delegate is just as the summary says: Represents a method that defines a set of conditions and determines whether the specified object conforms to those conditions.

A condition is specified by means of a delegate.

In the code: predicate instance findpredicate points to Method Isbookcatagory (), which defines a decision condition.

list<string> bookcategory = List.   FindAll (findpredicate); The FindAll () method finds the condition that satisfies the findpredicate point.

Understanding of predicate