They are all from the Brassica family.
All of these are vegetables, clearly, and share many similar sections of the alphabet. They are also in similar families of plants.
Cauliflower has closely tight masses that are together on stems. With broccoli, these flower masses are more loosely distributed so you can see each space between stalks. Broccoli can be described as looking like trees, while cauliflower can be described as looking like a cumulus cloud. Cauliflower is white in colour with green leaves surrounding it. Broccoli can be dark green or have a purple streak through it. Cauliflower has slightly fewer calories in the same serving size. There is no vitamin A in cauliflower, however there is in broccoli.
The type of flowering head is different. Broccoli has loose florets. Cauliflower is a more solid mass. That also means that the cooking times are slightly different. Plus there is the color. Broccoli tends to be green while cauliflower tends to be white, although there are purple varieties of both. In addition, there are 2 types of plants called broccoflower, and that is a hybrid. Preparation of those is closer to how you fix cauliflower. The one looks like a light green cauliflower, and the Romanesque variety can be light green (or sometimes purple) has very interesting fractal designs.
Celeriac
a cauliflower has a flower in the middle and a cabbage doesn't
About 14 km !
The distance between Brussels (Belgium) and Rotterdam (the Netherlands) is: 75 miles or 121 kilometers
Ghent is 30 miles North West of Brussels
SkyEurope, CSA Airlines and Brussels Airlines all operate regular flights between Brussels and Prague
Ebb to Brussels approximately 3880 miles which is around 6245km
Google maps says about 600 km between Brussels and Hamburg.
The distance between Reykjavik, Iceland, and Brussels, Belgium, is 1,320 miles. (2,125km).