This component allows you to take picture that will be analyzed for text recognition. In Salesforce, you will see the picture and the text contained.
If the workflow or the question hosting this component is set to create a lead or a contact, text contained on the picture will be automatically pushed to the different corresponding fields.
This is all automated, our OCR will do its best to identify email, phone, name, etc. Of course this works better with business cards and fairs badges.
In case a picture can't be taken you can give the opportunity to user to type the information in bulk. This input just helps you direct the user to tell him what to enter : serial number, contact info, etc
Please see the detailed article on SalesForce actions.