Collections are groups of similar products in Shopify that help merchants organize and filter their products into different buckets. For example, red short sleeve shirts. When you create a collection there will be a webpage www.yourstore.com/collections/redshortsleeveshirts. There could be some SEO benefits to creating different collections like this that are worth trying out.
Running in the background of Shopify is sitemap.xml. This is a machine-readable index of every single page on your site. If you create a collection, that collection will be automatically added to sitemap.xml.
Then, when you register your site with Google Search Console, you give it that same site map and it will check that periodically to make sure it has everything indexed. What could happen is that it helps your SEO, rank and the search phrases you are targeting. It may take a bit of time for everything to get indexed and work.
Help Doc: Finding and submitting your sitemap