A dynamic collection always requires a connection to the server PicApport. There, the query for the collection is stored. Is a dynamic collection called, it is as if you type the query again in the search bar.
Local collections were introduced in version 3 PicApport. This makes it possible photos directly in the browser of the device (smartphone, tablet, PC) which is currently being used to store. Locally stored photos can also be displayed if no connection to the server. similar to dynamic collections of the text of the query is also stored here. When you synchronize a local query to this server sent and any newly added photos are downloaded automatically. The photos are on the phone to save space scaled down to the Supported by the device screen size.