I want to understand the importance of :Application note" section of a journal, Is it same as publishing a research article and have the same value (in terms of Impact factor of that journal) as research article?
This is from the editorial statement of Bioinformatics: "Application Notes focus on shorter papers, exploring the applications used for experiments."
There are two important points here, the first being that the paper is short, the second that this sort of article is meant for a particular form of such a paper.
This is from the editorial statement of Journal of the American Society for Mass Spectroscopy: "Application Notes (four printed pages) are brief descriptions of technical advances in sample handling, instrumentation, data processing, interpretation of spectra, etc., that will be of interest to some segment of the mass spectrometry community."
The key thing here is that the paper is limited in length and should have a particular focus, as mentioned.
There is otherwise nothing that makes these "Application notes" different from regular journal papers, so in terms of "impact" it has the same value. The fact that the paper will bear the tag "Application note" is meant as a signal to the readers that it is a shorter paper than the usual ones and that it has a more narrow (and specific) scope and focus.