In SharePoint 2010 we can have two types of solutions one is Sandboxed Solution and Farm Solution while developing a solution in Visual Studio 2010.
One major difference in the deployment is Farm solutions are installed and deployed. Sandboxed solutions are uploaded and activated.
– Farm solutions are hosted in the IIS worker process (W3WP.exe).
– If you run any code in farm solution the whole farm will got affected.
– If you deploy any feature or retract any feature the whole application pool got recycled.
– Since they are scoped as farm level, they have full trust access to all the resources.
– When the Sandboxed Solution property is set to False, selecting Build\Deploy will deploy the solution to the Farm Solution Gallery.
– Sandboxed solutions are hosted in the SharePoint user code solution worker process (SPUCWorkerProcess.exe).
– The process runs under a CAS policy that restricts programmatic access to any resource outside the sandbox.
– Never restart the IIS application pool.
– If you run any code it will affect only the site collection of the solution.
– Helpful if you have shared hosting.
– When the Sandboxed Solution property is set to True, selecting Build\Deploy Solution deploys the solution to the site collection Solution Gallery.
Hope this helps…Happy Coding!!!!