Design principles are those principles that are followed while designing software systems for any platform by making use of any programming language. SOLID principles are the design principles that we follow as guidelines to develop robust, extensible and scalable software systems. These apply to all aspects of programming.
Design Patterns are the reusable template solutions for commonly occurring problems that can be customized as per the problem requirements. These are well-implemented solutions that are tested properly and are safe to use. Factory Design Pattern, Singleton pattern, Strategy patterns are a few of the examples of design patterns.
