Talking about packages in regard of Meteor is different from other languages. Meteor uses five basic types of packages.

• Meteor platform packages : The Meteor core itself is split into different Meteor packages. They are included in every Meteor App and you do not need to explicitly add these.
• Regular Meteor packages : These are also known as “isopacks“ or isomorphic packages and they work both on client and server. First-party packages such as accounts-ui or appcache are developed by Meteor core team comes bundled with Meteor.
• Third-party packages : These are the isopacks developed by other users and uploaded on Meteor’s package server. You can browse them on Atmosphere or with meteor search command.
• Local packages : These are the custom packages you create yourself and place them in /packages directory.
• NPM packages (Node.js Packaged Modules) : These are Node.js packages. They do not work different with Meteor but these can be used by previous types of packages.