Roughly speaking, there are three categories of fume extractors. The first category are the compact, small, air displacement extractors. These are suitable for a single workplace, generally have minimal suction power and usually contain only an active carbon filter. This filter only filters the larger particles from the fumes, other particles are simply blown back into space at the back of the fan, sometimes with the help of a short hose.
The second category is the tip extraction. This is a small tube that is mounted on the soldering iron close to the soldering tip. It works very effectively and, when used properly, captures (almost) all particles and gases. Here too, however, the filter is not sufficient to filter small particles and therefore sends them back into space.
The last category are the large fume extractors. These are the more professional solutions with more advanced (multiple) filters and sometimes expandable to be used for multiple workplaces. Of course the price is a bit higher than for the other two categories.
Smoke extraction during soldering