How to make a change to just one specific section
Changes to a section's design are handed by clicking the `Edit` button in the section's toolbar, then clicking the `Layout` tab in the sidebar. And, by default, any change made to a section of a certain type (text, image gallery, contact form, etc) and layout (grid, stack, 2-column, etc) will propagate throughout the entire website.
For example, if you make changes to an image gallery section that uses the `Grid` layout, those changes will also affect any other image gallery section that uses the `Grid` layout, as well.
Alternatively, if you'd like to make changes to *only* a specific section, you can use the "Local Overrides" tab, found just above the area where the section's properties can be changed.
From there, you can override the default design properties with values that are unique to a single section, without having to worry about affecting others.