Beside the more seldom use as an adjective (or so called adjectif verbial), the main use of participe
présent is to shorten subordinate clauses as an adverbial.
En pleurant elle lui raconta toute l' histoire.
Here the participe présent can have the functioin of a conditional clause, temporal clause,
causal clause or for descriptions of manner. As you will see the use is very similar to the English one.