Architectural patterns are essential frameworks in software design that provide reusable solutions to common problems encountered in software architecture. They serve as blueprints, guiding developers in organizing components and defining their interactions within a system. By employing architectural patterns, teams can enhance scalability, maintainability, and clarity in their projects. Common patterns include Layered Architecture, Client-Server, Microservices, and Event-Driven Architecture, each with its unique strengths and weaknesses. Understanding these patterns is crucial for making informed design decisions that align with project requirements and facilitate efficient development processes.