Bold and light cross snap,
I’m wondering if there is a difference between the nearest snap (cross sign X) as it gets bold or light as shown in the screenshot below.
I’m not sure where to find an explanation for all notations that appears to help while working in the Revit. For example, what does the dashed line below indicate for?
That blue dashed line represents the "Location line" parameter that you can see in the wall's properties. Center of core, wall centerline, finish face: exterior, etc.
For the other question, Wiki Help can help:
But what the bold and light cross indicate for? i.e., why it is sometimes bold and other light?