Cameras typically offer 2 types of zoom, with some offering both. Optical zoom is the only one that matters, as digital zoom basically robs you of resolution by simply cropping the image to show the “zoomed” pixels only. True PTZ cameras will have optical zoom with a motorized lens that adjust for wide and telephoto shots. The amount of zoom, typically specified, for example as “3x” indicates the variation available as the lens distance from the imaging chip is adjusted. While this gives you a rough idea of the amount of zoom available, a better and practically useful specification is the Horizontal Field of View Angle (HFOV) range. This is typically specified, for example as “5 degrees to 45 degrees”. This range, (if accurately specified by the mfg/marketer!) should allow you to figure out exactly what any camera will capture throughout its zoom range.

Looking at your space and your application, you will hopefully be able to focus on one end of this range and easily select a camera. However, your application may have needs that span the entire zoom range (e.g. a long Boardroom table that is also close to the camera). In this case, you will have to compromise on one end or the other but still try to find a camera that offers the best compromise (e.g. a 5-70 degree HFOV range would provide good headshots and capture all but the closest seats to the camera equally well).