Code Access Security:
- This is partial trust model.
- The assemblies will be deployed to the bin directory of the corresponding SharePoint web application.
- The solution will be scoped to the web application only, not to the farm level.
- Any other files like resource or image files will be deployed to the SharePoint root directory.
- In case of Full trust the assemblies in your solution are deployed to the global assembly cache on each Web front-end server and application server in the server farm.
- Here the code will run with full trust and runs without any code access security restrictions.
- Here the solution will be available to any web application on the server farm.