Do design patterns have to rely on OOP concepts?

Absolutely not . It doesn’t have to be tied to object-orientation (OOP).

Understanding design patterns requires understanding basic object-oriented concepts . If you’ve done development with Java, C++, or C#, you’ll be familiar with the following concepts: Decomposition is the process of dividing a problem into smaller pieces—in other words, divide and conquer.

Based on the purpose, design patterns were classified into three types. Creational — Concerns the way objects and classes were created. Structural — concerns the composition of classes and objects. Behavioural — characterizes the ways in which classes or objects interact and distribute responsibility.

Creational design patterns are concerned with the way of creating objects. These design patterns are used when a decision must be made at the time of the instantiation of a class (i.e. creating an object of a class). This pattern can be further divided into class-creation patterns and object-creational patterns.