Very briefly: the overview spectrum with lower resolution tells you the elementary composition of the surface while the high resolution analysis of individual bands mey help you identify the number and relative importance of chemical environments of the given element.

Thank you very much for the reply. If you can recommend any source references or books, kindly share the link. The main source that we are using to identify the energies is XPS simplified. if there is any other source, please share.

https://www.ethz.ch/content/dam/ethz/special-interest/chab/icb/van-bokhoven-group-dam/coursework/Characterization-Techniques/2015/xps2015.pdf

https://mmrc.caltech.edu/SS_XPS/XPS_PPT/XPS_Slides.pdf

Here is a book:

https://www.cnyn.unam.mx/~wencel/XPS/MANXPS.pdf

here is a website where you can find intorductory information on almost all elements:

https://xpssimplified.com/periodictable.php

Nevertheless XPS has sevral trick (I am not an XPS expert only used it in several cases during my career), therefore I suggest you to discuss your specifric problems (backgprund fitting, peak deconvolution etc.) with experts before you publish it.

See also answers to this question:

https://www.researchgate.net/post/How_can_a_beginner_learn_the_analysis_of_X-ray_photoelectron_spectroscopy_XPS_by_himself

Thank you Gyorgy Banhegyi and Jürgen Weippert for the valuable assistance.