Density Based Clustering Method:

 In density based clustering method
a cluster is a dense region of objects that is surrounded by a region of low
density. In the DBSCAN density based clustering algorithm  the points
in the low density regions are classified as noise and omitted.


Classification
Classification also known as supervised learning is the process of finding a set of
models or functions that describe and distinguish data classes or concepts where
the models derived based on a set of training data

Decision Tree Based Classification Methods:

A
decision tree is a way of representing a series of rules that lead to a class
or a value. The decision tree nodes are test values that need to be decided
or questions that need to be answered in order to decide the branches that
should be followed depending on the decided value. Each node may have
two or more branches. Each branch will lead to another decision node or to
the bottom of the tree, which is called the leaf node.To assign a value to
some class or case, the navigation process starts at the root node and moves
to each subsequent node and decide which branch to take until reaching the leaf node.