A collection view layout presents the visual grouping of the items in your collection. Layouts are intended to be modifiable to allow you to display a small to a large collection. You can display a different number of products per row on your mobile phone or desktop device.
This procedure is applicable in both themes 2.0 and 3.0.
STEP 1. From your Shopify admin, select Online Store.
STEP 2. On the right portion of the page, click on Customize.
STEP 3. On the top menu, select Collection pages from the drop-down list.
STEP 4. On the left panel of the page, tap Collection pages.
STEP 5. Modify the view layout of your collection by altering the number of rows and products per row in your devices.
STEP 6. Tap Save to keep your changes.