Sandboxing is akin to what Apple enforces in iOS. Developers are only allowed to use a prescribed set of APIs that exist in a sandbox, and there's no data permanence nor the ability to access resources or data outside of that sandbox. The advantage is security and stability (there's no way for a malicious app to delete your home folder, for example) but the disadvantage is limited application functionality (a sandboxed app can't directly access to any files or frameworks on the system, nor can it access the network or any devices.)