Prim's algorithm is used to find a minimum spanning tree. It is very similar to Kruskal's algorithm of finding shortest path in a graph. Prim's algorithm starts from a vertex and then keeps following the minimum distant edges to discover vertices, given that the vertex was not discovered before. Current implementation uses a simple and straight implementation in java. It can be further improved by improving sorting algorithm and using Min-Heap data structure for vertices. Those are not implemented to keep it simple enough to understand for all.

Dijkstra's algorithm is a known graph algorithm.

Dijkstra calculates shortest path to all the vertices starting from a single vertex. It's running time can be improved by using efficient sorting and more efficient data structure. But, for simplicity to make the implementation easy to understand for all, current implementation in java follows very simple sorting algorithm and simple data structure.

DFS or depth first search is a very common graph searching/traversing algorithm in graph theory. It is implemented using a stack. However, a recursive version is also possible. Current implementation in java makes use of Graph and Stack classes developed previously.

Graph is a data structure used in many algorithms. It's vertices are represented by a separate class, Vertex. There is a data (Object type) field in vertex class, which can be used to store any data. Vertex class can be modified to hold any information (e.g. Student, Account, etc.) by using the example.