What’s a Package?

Each second-generation managed package follows a distinct life cycle. You add metadata to a package, and create a new package version. While the package is continually evolving, each package version is an immutable artifact.

A package version contains the specific metadata and features associated with the package version, at the time it was created. As you iterate on your package, and add, remove, or change the packaged metadata, you create many package versions.

You can install a package version in a scratch, sandbox, trial, developer edition, or production org. Installing a package version is similar to deploying metadata. Each package version has a version number, and subscribers can install a new package version into their org through a package upgrade.

You can repeat the package development cycle any number of times. You can change metadata, create a package version, test the package version, and distribute it to your customers via AppExchange. This distinct app development life cycle lets you control exactly what, when, and how your metadata rolls out. In the installed org, you can inspect which metadata came from which package and the set of all metadata associated with a specific package.