Coffee beans are actually seeds found inside the fruit of the coffee plant, called a coffee cherry. What ends up in your cup is a seed that has been harvested, processed, roasted, ground and brewed.
The Simple Guide
Coffee starts as a red or yellow fruit growing on a coffee tree. Inside each cherry are usually two seeds — the "beans" you're familiar with. Farmers harvest the ripe cherries, remove the fruit around the seed, and dry the seeds. Those green (unroasted) seeds are then roasted, which is what turns them brown and develops the flavors we associate with coffee.
Why It Matters
Because coffee is an agricultural product — like wine grapes — where it's grown, how it's processed, and how fresh it is all shape what ends up in your cup. Understanding the journey helps explain why two bags of "coffee" can taste completely different.
What To Do
Next time you drink a cup, think about the journey it took to get there. It helps to know roughly where your coffee is from and how recently it was roasted — both are usually printed right on the bag.
Coffee cherries usually contain two flat-sided seeds. Occasionally a cherry produces just one round seed instead — called a peaberry. Some roasters sort these out and sell them separately for their more concentrated flavor.