android - What is the main use of Content Providers in multiple apps -

i have been reading content providers while , have seen of 2 types, 1 in built eg contacts(that understood) , other making our own content provider content:// thing. of examples have gone through doing in 1 app. mean point of using content providers if store data in 1 app , retrieving in same definition says shares data between apps?

i looking made 2 projects , used content provider in 1 , store data in database. make other project , stored data through content :// uri . main function of content provider? thing possible? if how? have been asking clear basics.

i believe looking information on content resolver. others pointed out, provider sharing app's data. when want access it, in app, use content resolver send commands other app's content provider; insert(), update(), delete(), , query().

what spoke of content://uri, that's identifier name of data looking in content provider. link explains providers, resolvers, contracts, uris, , how create them.

http://www.grokkingandroid.com/android-tutorial-writing-your-own-content-provider/