Overview and Difference between Sandboxed solution and Farm solution For SharePoint Project Type in Visual Studio 2010

Overview and Difference between Sandboxed solution and Farm solution For SharePoint Project Type in Visual Studio 2010

In SharePoint 2010, we can create two types of solution

1>     Sandboxed Solution

2>     Farm Solution.

So what is difference between these two solutions?

Sandboxed solutions: Run in a secure, monitored process. Sandboxed solutions can be deployed without
 requiring SharePoint administrative privileges. If you choose a sandboxed solution, you can only use
project item types that are valid in sandboxed solutions.

Farm solution:  In this solution all SharePoint project item types in are available, but deployment
needs administrative privileges and the solution must run in FULL TRUST permission LEVEL.

Which solution needs to select?

Sandbox solution is best because of following reasons.

·         It will deployed at the site collection level rather than the farm level,
      so it allows us to this lets you separate a solution so it is only offered to
      one site collection within the farm.

·         Sandboxed solutions also run in a separate process from the
      main SharePoint IIS web application process,
       and the separate process is throttled and monitored with quotas to guard the
     SharePoint site from becoming unresponsive due to a misbehaving sandboxed solution.

·         Users can deploy solutions not including requiring administrator agreement

Many useful features provide by Sandboxed solution then why we need Farm Solution?

If Code requirements to run at the Web Application of Farm Level or talk with multiple site collection,
 in that case we should go for Farm Solution