The typical notebook is white inside, ruled, with a cover in some color. The picture on the front changes and not much else. But there are five kinds that change how a notebook is used, and each one solves a different problem. One of them is the kind we make, so we're not neutral here. For all five we also say what they don't do well.
Reusable
The pages are made of a synthetic material and you write with heat-sensitive ink pens, Pilot's FriXion. You scan the page with your phone and wipe it clean with a damp cloth. The best-known brand, Rocketbook, started in 2015 with a version you erased in the microwave. The detail worth knowing is that this ink turns invisible above 60 °C, and the pen's own maker warns against leaving written pages in a hot car. They're good for notes you'll move to a computer. They're no good for anything you want to keep on paper.
Disc-bound
Instead of a spiral or stitching, the pages hang on a row of discs by mushroom-shaped cuts along the edge. You pull them off and press them back with your fingers, so you can reorder the whole notebook. The system is Belgian, from 1948, and it's called Atoma; other brands adopted it later. It's ideal for anyone who organizes projects by section. The downside is that adding your own paper takes a special punch, and moving many pages at once is slower than with a ring binder.
Stone paper
It contains no tree fiber. It's about 80% calcium carbonate, which is ground stone, bound with a plastic resin. The result is a very smooth sheet that resists water and is hard to tear. It takes ballpoint and gel well, and fountain pen ink is slower to dry on it. The environmental side is the part people argue about: because it contains plastic, it can't be recycled with ordinary paper and isn't biodegradable, and some paper scientists consider it more plastic than paper. It's a good choice if you write outdoors.
Handmade
These are sewn by hand with techniques that are centuries old. Coptic stitch, used by the early Christians of Egypt from the 2nd century, leaves the spine exposed and lets the notebook open 360 degrees without a drop of glue. Japanese four-hole binding, sewn through the cover, is one of the most striking. Many use cotton paper or lokta, made from the bark of a shrub that grows in Nepal. Each one is different, and that's what you pay for. Handmade paper varies from one sheet to the next, so test your pens before you get attached.
Colored pages
Here the difference is in the paper. Drawing on a colored ground is older than the printing press: blue paper was already made in Italy in the 14th century, and by the 1500s Venetian artists were drawing on it with white highlights. Today the most common is black paper, almost always in drawing pads. Notebooks in a saturated color all the way through are few.
Bocetta is one of them. Cover, pages, edges and ribbon are the same color, black or cobalt blue for now, and you write in white ink. It measures 17.6 × 24.5 cm, has 160 blank pages and is sewn. What it doesn't do well: it isn't for your everyday ballpoint, and for long notes in small handwriting a white page reads better.
How to choose
By the problem you want to solve. If you lose your notes, reusable. If you reorganize all the time, discs. If you write in the rain, stone. If you want a one-of-a-kind object, handmade. And if what bores you is the white page, color. See the Bocetta notebook or browse all the colors.
Sources: the Rocketbook story, Pilot's FAQ on FriXion ink, Wikipedia on disc binding, Martin Hubbe in BioResources on stone paper, Wikipedia on Coptic binding and the University of St Andrews exhibition Venice in Blue.