Organisms can reproduce in two different ways either through sexual reproduction which involves the fusion of two gametes like a sperm and an egg and so leads to genetically different offspring or through asexual reproduction which uses mitosis to form an identical clone of the parent organism.
The two main benefits of asexual reproduction are that only one parent is needed and the process is very quick this allows a single organism to quickly colonize an entire new area.
The downside of asexual reproduction is that because all the offspring are clones there isn't any genetic variation this means that if a new disease comes along and one of the offspring is susceptible to it then chances are that all of them will be susceptible which could wipe out the whole population.
The main benefit of sexual reproduction is that it leads to loads of genetic variation within the population in the short term this means that the population is less likely to get wiped out by a single event like a new disease because some individuals will be more resistant to it than others.
In the longer term, sexual reproduction allows for evolution to take place and remember evolution is just the process by which species change over time because the most favorable traits are most likely to be passed on each generation.
The main disadvantage of sexual reproduction is that it takes a lot more time and energy than asexual reproduction does for example animals have to first of all find their potential mates where it can be time-consuming and and they also need to impress their mate.