What are the 3 types of ladders?

What are the 3 types of ladders?

Ladders come in a range of styles to suit the different jobs they can be used for: Single Pole Ladders (maximum length 9 metres) Extension Ladders (maximum length 15 metres) Step Ladders (maximum height 6.1 metres) Dual Purpose Ladders (stepladder hinged to provide an extension) Platform (podium) Ladders.