One area where big data analytics is being used is healthcare. Healthcare analytics have the potential to reduce costs of treatment, predict outbreaks of epidemics, avoid preventable diseases and improve the quality of life in general. Suppose that you are a senior employee of an IT company and you have been requested to present on big data in a workshop to recent medical doctors being recruited. Your chief executive officer $($CEO$)$ has requested you to explain the meaning of big data, the characteristics of big data and how big data analytics can help in the medical field. Describe the terms that your CEO has requested you to present and explain how big data analytics is being used in the medical field. $[13$ marks$]$

$($b$)$ NameNode and DataNode play an important role in the Hadoop File System $($HDFS$)$ of the Apache Hadoop ecosystem. Elaborate on the roles of the NameNode and DataNode. $[6$ marks$]$

$($c$)$ To abstract complexities of Hadoop programming model, a few application development languages such as Pig, Hive and Jaql have emerged that build on top of Hadoop. Differentiate between these three languages in terms of types of languages, data structure supported and schema. $[6$ marks$]$