In this lesson we'll take a look at importing packages from both within Unity and from an external source. Importing packages will be fundamental to bringing in your own custom assets such as 3d models, animations, UI elements and so on. Packages are just collections of different types of assets. So a character may have textures and animations included in one package but a package can also include one asset like an audio clip. Importing and exporting packages will be a typical thing when building your game in Unity.
Note: The latest versions of Unity no longer have built in packages but must be downloaded from the asset store. Here is the link to the Standard Assets: https://assetstore.unity.com/packages/essentials/asset-packs/standard-assets-32351