The chemical additives in chemical toilets cause them to pollute the environment and the user depends on special disposal stations. You get by without chemical additives. The water consumption of mobile toilets with water flushing varies. In addition, the variation requires a water connection.
The alternative: dry toilets.
A dry toilet is a toilet without water flushing. If the feces are separated, one speaks of separation toilets. If the feces are collected in a container, it is a earth toilet. A humus toilet goes a step further by composting the feces.
Composting toilets are separation toilets where the solids are composted.
If urine and feces are not separated, unpleasant odors can develop. Such variants should therefore have an exhaust air system. After composting, the excretions can be used biologically as fertilizer or disposed of micro-biologically harmlessly.
All separation toilets are dry toilets. But not all dry toilets are separation toilets. And all composting toilets are dry toilets but not necessarily always separating toilets.