Concrete curing
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Looking after fresh concrete in its first days: keeping people off it and stopping it from drying out too fast, so it hardens properly and doesn't crack.
Concrete doesn't harden because it dries, but because the cement reacts with water. If the water leaves too fast, for example in summer sun or wind, the surface ends up weaker and fine cracks open easily.
That's why fresh concrete is often kept damp, covered or shaded for the first days. It also has to be kept off: on a sidewalk or path, a board or a tape blocks the way while it sets.
If paint or another layer is going on top, the concrete must first have hardened and dried properly. Ask when it can be walked on and when it can be painted.