Ask ten guitarists what makes one acoustic sound different from another, and "tonewood" comes up almost every time. It's a genuinely important part of the story, though not the whole story. Here's a plain-English rundown of the timbers you'll come across most often, and roughly what they contribute.

Spruce (tops)

Spruce, particularly Sitka and Engelmann varieties, is the most common top wood on steel-string acoustics, and for good reason. It's stiff relative to its weight, which lets it respond quickly and project strongly, with a bright, clear character that has a wide dynamic range from a gentle fingerpicked passage to a hard strum.

Cedar (tops)

Western red cedar is a popular alternative top wood, generally warmer and slightly more responsive at lower playing volumes than spruce, with a softer onset to each note. It's a favourite among many fingerstyle players for that reason, though it can compress a little more than spruce under very hard playing.

Mahogany

Used for both backs and sides, and occasionally as a top wood itself, mahogany tends to produce a warm, midrange-focused tone with a fairly quick, punchy response. It's closely associated with a lot of classic blues and folk recordings, where that direct, present midrange cuts through nicely.

Rosewood

Rosewood, most commonly East Indian rosewood these days, is prized for its rich low end and complex overtones, generally producing a wider, more scooped tonal profile than mahogany, with pronounced bass and sparkling highs.

Maple

Maple is a denser, more tonally neutral wood, often chosen specifically because it doesn't add much colouration of its own. This makes it a popular choice for guitars intended to be heavily amplified, since a more neutral acoustic tone translates more predictably through a pickup and PA system.

Koa

A Hawaiian wood, koa produces a tone often described as sitting between mahogany and rosewood, warm but with good clarity, and it's also prized for its strikingly beautiful figured grain.

How much does wood actually matter?

Tonewood is a genuine factor, but it's one piece of a bigger picture that includes the guitar's bracing pattern, body shape and size, construction quality, and even the strings you put on it. A well-built guitar in a "less prestigious" wood will often outperform a poorly built guitar in an expensive one. Tonewood is worth understanding and paying attention to, but it's not the single deciding factor people sometimes assume it is.

Choosing by ear, not just by spec sheet

All of this is a useful starting point for narrowing down what you might like, but tonewood descriptions are generalisations. The only reliable way to know how a specific guitar actually sounds is to play it yourself, since two guitars built from identical timber can still sound noticeably different from one another.