How are primary and secondary succession similar and how are they different?

Primary and secondary succession are different based on the manner in which they are formed. Primary succession  is the type of succession which starts in a barren area,where there is no soil that can sustain the growth of plants. In primary succession, lichen are usually the first type of plant to occupy the area, that is why they are called pioneer species. Overtime such areas undergo series of change to become a matured ecosystem.
A secondary succession is a type of succession that occur when an already established ecosystem is reduces to a smaller population size or wiped out by a natural disasters such as fire outbreak or flooding.
Primary succession is a process that takes a very long time to occur [such as hundreds of years] while secondary succession occurs much faster.

They are similar because they are both going through with an action and they are different because one is main and one is put off to the side until primary is finished. Brainliest pls! :)

Im assuming this is a multiple choice answer what is the answers to chooce from?