Before you decide how to bet, you have to know what the board can do to you, and to your opponent. Two flops that look similarly "random" can play completely differently: one where almost nothing beats top pair, and one where a flush or a straight is always live. That difference is board texture, and reading it fast is the first step in almost every postflop decision, not an afterthought after you've already picked a bet size.

What makes a board wet or dry

A board's texture comes down to two things: what suits are showing, and how close together the ranks are.

Suits: three cards of the same suit (monotone) puts a flush in play for anyone holding two of that suit — the wettest a board can be on suit alone. Two of a suit (two-tone) adds a real but narrower flush draw. All three different suits (rainbow) removes flushes from the picture entirely.
Connectivity: ranks bunched close together open up straight draws in both directions. Ranks spread far apart, or a paired board with only one or two distinct ranks in play, close most of them off.

A wet board carries real draws — a lot of hands can improve, so bet sizing and continuation strategy need to account for that. A dry board rarely improves either player, so the decision tree stays simple.