Hive Context: org.apache.spark.sql.hive.HiveContext
Spark SQLContext: org.apache.spark.sql.SQLContext.
Following are the reasons you need to use hive context, if you want to
Use hive metastore tables/views
Launch thrift server
Run window functions (rank, dense_rank, lag, lead)
Use hive udf
Persist the table schema for Spark SQL
Enable thrift JDBC service for Spark SQL
HiveContext is more battle tested.
Spark 2 is introducing window functions natively and would be compliant with ANSI SQL 2003 standard.