What's the difference between office and retail?

[Jeff Kehl]

I have a property on a busy street that could be used for what I would consider either office or retail use. In fact there are properties right around it that are used for both, a flower shop, a tattoo shop, an accounting office, an insurance office all in the same type of properties right next door. 

So that got me wondering is there some kind of criteria used in classifying properties as office or retail? Is it if you sell a service or product? Is it if the business works in a high visibility site versus one slightly off the beaten path?