It is a term you will find a lot on marketing blogs: online presence. There are lots of factors that come in to play, but in the end it all boils down to one thing. The stronger your online presence is, the stronger and more professional your brand is presented online to your (potential) customers.
The online presence usually starts with your own website. It needs to have a look and feel that corresponds with your brand identity, which appeals with your clients. But maybe you also have a Youtube channel, or perhaps multiple social media accounts. Then there is the offline marketing (flyers, posters, etc). How are you going to make sure all these channels of external communication are going to stick to your brand identity?
It really is quite simple: create a brand book, put it online and share it with all relevant parties while keeping it under your control. Keep it centralized so that when you update your logo, they all get the new logo straight away. No more emails with attachments ranging from “logo-v1-final” to “logo-v1.1-draft-final-approved”.