This may seem like a bit of stupid question. The obvious answer is, of course, that a smaller air compressor is suited to jobs require compressed air at lower pressures; for example, pumping up an inflatable mattress or a bicycle tire. The largest air compressors are designed to fulfil industrial requirements, such as manufacturing processes.
However, there is more to this question than meets the eye. The lesser know answer is to do with the capacity of an air compressor. Capacity is to do with the air compressor being able to deliver compressed air at a particular CFM and particular air pressure at that specific CFM of flow.
Confused? To explain, lower capacity air compressors are unable to cope with applications which require a high capacity level and would eventually destroy itself trying to succeed. This is due to the fact it would be running to its full capacity but has a restricted duty cycle.
When choosing a suitable air compressor it is vital that you take capacity into account so that it delivers the correct pressure and flow of compressed air at the required pressure.