Difference between Salesforce and Salesforce1?

Question

If I were to explain to a lay-person, who is somewhat familiar to Salesforce, the difference between Salesforce.com and Salesforce1, without delving much into the technical aspects, what would be the best way to do so?

Answer 1

Both Salesforce.com and Salesforce1 can be accessed via a web client running on a PC, tablet, or phone.

Salesforce1 is optimized to work on a small touchscreen and can have functions via 3rd party apps to access iOS or Android features like GPS location data.