what is the difference between architectural and design pattern?

Architecture mostly addresses problems of distributed functionality, system partitioning, protocols, interfaces, scalability, reliability, security and... while design patterns are medium-scale and mostly language-independent abstractions using object oriented mechanisms and described by UML diagrams which solve commonly occurred problems in software construction. 

Design Patterns are well known patterns for solving technical problems in a way that has proven itself many times. Design patterns are common design structures and practices that make for creating reusable Object-Oriented software. Design pattern examples are Factory Pattern, Singleton, Facade, State, etc. Design patterns can be used to solve smaller problems throughout the application, and are much easier to inject, change, add than the overall architecture

architecture patterns are well known patterns for solving software application architecture problems. Software application architecture is the process of defining a structured solution that meets all of the technical and operational requirements. A pplication's architecture is the overall 'organization' of the code. Examples of different Architectures might be MVC, MVVM, MVP, n-layer (i.e. UI-BLL-DAL), etc. The architecture typically needs to be decided up front and often is difficult to change once the application is built.