My name is Aaron, I'm a guru here at Shopify!
No problem at all! That's in your theme's language settings. To get there in Debut, in your admin go to online store > themes and click on the button with three dots; that will give you the option to edit language. Once there, you'll see some tabs across the top - click on the button with ellipses in those tabs, and then go to the Checkout and System section. Scroll down a bit - the setting you want will be under the Page titles heading. Find the field for Collections, and you can enter whatever you wish to see in that field!
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Aaron | Shopify Guru
I realize this this thread is old, but I'm new at this and I'm using the Debut theme.
I followed the instructions, but I cannot find any mention of "collections" in the section mentionned.
I really want to change the word "Collections" to "Product Catalog" but I cannot find any place where to do so, even after following these instructions for the Debut theme.
Thanks in advance.