dotplot analysis is not same to pairwise alignment. You can use Bioedit for pairwise alignment. a basic alignment tool

can you explain the need of both???? i confused with this.....

Dot-Plot is a method used for Pairwise Alignment or used to check the homology between two sequences. For more insight please refer "Bioinformatics: Principles and Applications by Ghosh & Mallick".

Dot-Plot analysis is a graphic interpretation of pairwise alignment. The convenience of using dot-plot analysis is that the one graphics shows all significant pairwise alignments simultaneously. Dot-plot is also very useful for searching the repetead fragments (e.g. resulting from gene duplication or multiple duplication) - in such case you compare one sequence to itself.

well said.