Let’s refer to Wikipedia for this definition
VOCs are organic chemicals that have a high vapor pressure at ordinary room temperature. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and enter the surrounding air, a trait known as volatility. For example, formaldehyde, which evaporates from paint and releases from materialslikeresin,hasaboilingpointofonly–19°C(–2 °F).
VOCs can be found in cigarette, plants, smog… essentially things that smell! The effects of them are hard to ascertain because symptoms are slow to develop. Keep in mind that paints which are LOW or NO VOC can still have an odor but they are not going to make you sick.
Pretty much all paints are within the safe VOC range with some having NO VOC. There are still paints on the market which don’t fall into that “truth” like shellac and they need to be used carefully and in well ventilated areas with masks.
There is a lot more to VOCs than mentioned here but know that any latex you buy for your home is going to be safe (check out or blog post on latex and oil paints).