Designers use it to visualize the look (or mood) the would be going for in a design. They collect examples of images that all go into the same rough direction t

Designers use it to visualize the look (or mood) the would be going for in a design. They collect examples of images that all go into the same rough direction they could be going for in a design and collect those into one moodboard. Then they would contrast that with a different direction on a second moodboard. And oftentimes more than two directions. These help them to narrow down potential avenues to explore further. Either for themselves or especially with a client. Clients often profit from the visual aspect enabling them to point out what they like (and especially what they do not like). The designer can then ask questions regarding what especially they like, if it is the color, the combination of colors, the way the font is set and so on. From there the designer starts their own exploration of what they learned from the client (or from asking themselves the same questions). It's a tool for exploring a space of vast possibilities and narrowing them down onto a manageable level. [Edit] * Disclaimer * I am not a Designer. But I've worked with quite a few and found moodboards to be a helpful tool. But they can have their drawbacks when clients fall in love with one or two specific examples in a moodboard and are disappointed because the designer's own exploration will necessarily differ from those.