DropDown's each Item has 2 things
1) DataTextFiled: The text that is displayed in the dropdown for the user to select.
2) DataValueField : The Value for that Item/ Text displayed which can be used by the programming logic .
These are just the basic representative of HTML DropDownList called as <SELECT>
Here in the above snippet :
Volvo : DataTextField
value="volvo" : DataValueField
and rest is databinding concept introduced by asp.net as you said for the Data Providers.