A Virtual Assistant or virtual assistant is a person who provides services to businesses from an external location. A virtual assistant will typically take care of administrative tasks for you, whether it's support, accounting or the like.
It is also common to use a Virtual Assistant if you need help with marketing. A virtual assistant can, for example, help your company with social media updates, or with the production of other marketing content.
In other words, a virtual assistant can help you with most things. The person may not be able to fetch you a cup of coffee and place it on your desk. However, he or she can order coffee from the canteen and arrange for it to be delivered to you.