Below is the description of the both.
def createTempView(viewName: String): Unit
Creates a local temporary view using the given name. The lifetime of this
temporary view is tied to the SparkSession that was used to create this Dataset
def registerTempTable(tableName: String): Unit
Registers this Dataset as a temporary table using the given name. The
lifetime of this temporary table is tied to the SparkSession that was used to create this Dataset.

From the image you can see registerTempTable is deprecated in Spark 2.0. Means registerTempTable was the feature prior to Spark 2.0.