Collections make it easy to save and organize photos as you search. They're similar in concept to a lightbox on other image licensing sites, just with a more modern name.
Create collections around projects or ideas that you're working on. You can view your collections by clicking on your avatar (or username) in the top right corner of the navigation bar. Then select "My Collections" from the dropdown menu.
To collect a photo on the website, hover over the photo you would like to add to a collection and click the "+" in the gray bar at the bottom:
A list of your collections will open up. Hover over an existing collection and click "Add" to add it to a collection you've been working on:
To create a new collection, begin typing the name into the bar at the top that reads "Find or Create Collection" and click the blue "+" to create: