Wait or Stay are very important for your dog to understand in many situations and is one of my top 3 commands that I ensure all my dogs that come to me for training understand and use.
It is a very easy way of keeping your dog safe in more situations than you realise.
Giving your dog another command also opens up your dialogue with them so you can start to form a working relationship whereby they look to you for what to do next and this wonderful bond begins to form.
The PDF goes over many ways on how to achieve the wait or stay and which word to use for different situations