Specialty coffee bags carry more information than supermarket tins, and most of it is genuinely useful once you know what you are looking at.
Origin
Where the coffee grew. Country is the broad brush; region, farm or cooperative narrows it down. Altitude matters too - coffee grown higher ripens more slowly, which generally means more acidity and more complexity in the cup.
Variety
The botanical variety of the plant, in the same way grapes have varieties. Almost all specialty coffee is arabica. Robusta grows at lower altitudes, carries roughly twice the caffeine, and tastes heavier and more bitter - it has its place in espresso blends and instant coffee, but it is not what you will find in a specialty bag.
Process
What happened to the cherry after picking. This changes the taste as much as origin does.
- Washed - the fruit is stripped before drying. Cleaner and brighter, with the origin showing through.
- Natural - dried with the fruit still on. Heavier, sweeter, often berry-like.
- Honey or pulped natural - somewhere between the two.
Roast date
The single most useful thing on the bag, and the one most often missing. A roast date tells you how fresh the coffee is. A best-before date two years out tells you nothing at all - it means the coffee was roasted long enough ago that nobody expects it to taste of much.
Buy by roast date, not by expiry date. Coffee does not spoil; it just fades.
What to do with all this
You do not need to memorise any of it. Track what you enjoy over a few bags and the pattern usually shows up quickly - most people find they prefer either washed or natural, and that alone narrows the choice enormously.