Chimera’s metal honeycomb grids and Lighttools Fabric Grids are described in degrees. These degrees are roughly the angle of spread from the front of the lightbank they are installed on, though the light used and size of the lightbank will cause results to vary.
Smaller degree numbers are more narrow beam angles, meaning that the spread of the light is tighter and over a smaller area.
Larger degree numbers are wider beam angles with physically larger cells, these offer more spread of the light from the lightbank, meaning that the spread is larger.
A 20-degree grid will confine the light output to a more narrow beam, and 60-degree grid, will produce a wider beam.
Another consideration is that adding a grid to the lightbank also reduces output. Narrower beam angles, which have smaller cells will reduce more light than wider beam angles.