Are these sticky widgets Left-Nav and Right Nav Cart?

Hello! I’m a WP newbie, I’ve searched hundreds of wordpress sites, but none come close to the minimalism of:
If you have seen one please let me know :slightly_smiling:

Today I finally found information about the plugin sticky widget. Is that what the left-nav and the right-shopping-cart are? I like how different sections stick to the left-sticky nav then disappear.

Can I apply these widgets to any premium theme and completely hide/replace the premium’s themes 8 different menus?