Quantitative and qualitative Data.
Quantitative data is basically how much of something instead of the quality,such as a survey,How many people take a bus to school,ones this survey is complete you have obtained quantitative data.
Qualitative methods are ways of collecting data which are concerned with describing meaning, rather than with drawing statistical inferences.
What qualitative methods (e.g. case studies and interviews) lose on reliability they gain in terms of validity. (Taken From http://www.holah.karoo.net/quantitativequalitative.htm)