Actualizándolos
Actualizándolos is a term that, while not a formally recognized word in standard Spanish dictionaries, is understood in common usage to mean "updating them." This phrase is a combination of the gerund form of the verb "actualizar" (to update) and the pronoun "los" (them, masculine plural). The implication is that an action of updating is being performed on a group of masculine or unspecified plural items.
The specific context in which "actualizándolos" is used will determine what "them" refers to. It could be
The use of the gerund suggests an ongoing or continuous process. For example, a system might be