For wireless APs many units can be installed depending on the infrastructure and requirements.
For example on a building of multiple floors, each floor can have multiple APs.
For bridges, the connection can be point to point(one bridge connected wirelessly to
another) or point to multipoint (one to many).
It depends on the infrastructure. Some questions like how many users would require wireless? on what places of the facility wireless access is required? Noise and interference level on the required places, environmental factors etc. have to be
considered before designing any wireless network.
The best things would be to get a site survey done which would answer such issues better with exact recommendations.