Peat is an organic soil type formed by the accumulation and partial decomposition of plant matter under waterlogged conditions, characterized by a high content of organic matter, typically above 75%. Normally high in carbon also.
Around 40% of carbon sequestration from air through gas exchange of photosynthesis is used to feed microorganisms in soil. Helps to have carbon in soil.
Usefull to know how much of the peat is organic, has to be at least 35% to be considered peat anywhere up to 75%.
The more organic matter you got the higher meq cec soil will have. Soil will be better able to hold and store nutrients do make sure you only fert when you need to, don't just blanket feed every day because it feels good for no reason.
It's just a medium like any other , higher a cec the less frequent watering it needs also.
Good few pages in my diary with CECs if you would like to know more or do some research.