What is the difference between managed packages and unmanaged package in Salesforce?

Hi,

Managed Packages  are the ones where the Code is Hidden and Can be easily Upgraded or PUshed with new updates to the code where as Unmanaged Packages have the Code Visible and can be edited by the Org in which it has been Installed. Unmanaged Packages cannot be Upgraded or Pushed - they are like one time coded.

Hi
Managed Packages: Managed packages are typically used by salesforce.com partners to distribute and sell applications to customers. Once the components are installed from a managed package, the components cannot be edited in the organization they are installed in.
Unmanaged Packages: Unmanaged packages are typically used to distribute open-source projects or application templates to provide developers with the basic building blocks for an application. Once the components are installed from an unmanaged package, the components can be edited in the organization they are installed in.
Thanks