The word "via" is a preposition used to indicate a method or means of doing something. It often implies that something is being done by way of a particular route, method, or intermediary. For example, when saying "I sent the documents via email," it means that the email was the method used to send the documents.
The word "via" comes from Latin, meaning "way" or "road." It has been adopted into English and maintains a similar meaning, indicating a path or method of passage.