Google Merchant Center can be used to:
Update mobile bids for products
Set campaign priority for products
View competitive benchmarks for Shopping campaigns
Manage shipping settings for a store
You can set shipping settings when uploading data feed.
Google Merchant Center is a tool that helps you upload your store and product data to Google and make it available to Google Shopping and other Google services. By linking your Google AdWords and Merchant Center accounts, you will be able to surface your products directly to users through Shopping ads.
Read more here: https://support.google.com/merchants/answer/188493?hl=en