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 # Defining Data
 
+## Introduction
+Data are facts, information, observations and measurements that are used to make discoveries and to support informed decisions. A dataset, which is a collection of data may come in different formats and structures, and will usually be based on its source, ot where the data came from. For example, a company's monthly earnings might be in a spreadsheet but hourly heart rate data from a smartwatch may be in [JSON](https://stackoverflow.com/a/383699) format. It's common for data scientists to work with different types of data within a dataset. 
+
+
+This lesson focuses on identifying and classifying data by its characteristics and its sources.
+
 ## Pre-Lecture Quiz
 
 [Pre-lecture quiz]()
 
-# What is Data?
 
-#
+
+## The 5 V's of Big Data 
+
+
+
+### Velocity
+
+The speed at which data is collected.
+
+### Veracity
+
+The quality of the data. Was is collected ethically?
+
+### Variety
+
+Structured
+Semi-Structured 
+Unstructured
+
+### Value
+
+Is the data complete?
+
+### Volume
+
+The amount of data collected.
+
+## Sources of Data