Sitecore packages are used for different task like when you need to copy items from one Sitecore instance to other instance or you want to create a backup for some files or you wants to perform mass data migration then packages helps you a lot. It helps in lowering the development cost & time and also increases the reliability.
Sitecore packages are usually used for small Projects. For larger projects Team Development for Sitecore(TDS) is used. But why?
Here is the answer -
Suppose you created a package for some of the items and later you changed these item then you have to create the package again to update these changes. While if you make item changes in TDS then it will auto Sync these changes. Hence TDS is preferred over Sitecore packages.
Now I am going to tell you how to create packages in Sitecore -