Tell me about the principles of SOLID

SOLID is a set of five principles of object-oriented programming that help create flexible and maintainable systems:

• S (Single Responsibility Principle) — A class should have only one reason to change, meaning it should perform a single specific task.
• O (Open/Closed Principle) — Software entities should be open for extension but closed for modification.
• L (Liskov Substitution Principle) — Subtypes must be substitutable for their base types without altering the correctness of the program.
• I (Interface Segregation Principle) — Prefer many specific interfaces over a single general interface.
• D (Dependency Inversion Principle) — High-level modules should not depend on low-level modules; both should depend on abstractions.

Applying these principles helps create code that is easier to test, extend, and maintain.