The 12 column system is based on Bootstrap’s 12 column grid system. Using this system has more flexibility to create dynamic layouts and easily made to be fully responsive across all screen sizes.
The width of the screen is split into 12 equal columns covering 100% width. Learn more about the 12 column grid system
All images can be changed in the CMS collections settings. Except for 3 places: The home page, the firm page and the contact component. Click on the image and then go to the settings panel and click on replace image.
There are several CMS collections installed and ready to go and easy to navigate. They are in the CMS panel. All you need to do is create a new item inside of a collection by pressing the blue button in the upper right hand corner. Fill in any relevant information and it will automatically update the website. To learn more about all CMS can do visit Webflow's tutorial on CMS
Components are easy to drag and drop anywhere. Components are usually an item used across many web pages like the Navbar and Footer. There are 4 components already set up for this template used across multiple pages. Go to Webflow components to learn more abour how to use them.