Subscriber customization of packaged components
Key Takeaway
An org that installs a managed package can still edit certain properties, such as page layouts, and package upgrades won't overwrite those changes. An org that installs an unmanaged package can fully edit the components, but the package developer can't upgrade them.
A package is a container for apps, tabs, and objects. When an org installs a package, that org becomes the subscriber org. The solution provider decides whether to distribute the package as a managed or unmanaged package. The package type controls how the components behave in the subscriber org, including how much the subscriber can edit them.
What subscribers can edit in an unmanaged package
An unmanaged package hands its components over to the subscriber, who can fully edit them in the org where they are installed. The package developer, who uploaded the package, has no control over those components and can't edit or upgrade them.