I have a bibliography in following format the entries in file
@TechReport{mell62011,
author = {Mell Peter and Grance Timothy},
title = {Recommendations of the National Institute of Standards and Technology},
institution = {National Institute of Standards \& Technology (NIST), USA},
year = {2011},
}
@article{fernandes2014security,
title={Security issues in cloud environments: a survey},
author={Fernandes, Diogo AB and Soares, Liliana FB and Gomes, Jo{\~a}o V and Freire, M{\'a}rio M and In{\'a}cio, Pedro RM},
journal={International Journal of Information Security},
volume={13},
number={2},
pages={113--170},
year={2014},
publisher={Springer}
}
@article{de2019cyber,
title={Cyber-Storms Come from Clouds: Security of Cloud Computing in the IoT Era},
author={De Donno, Michele and Giaretta, Alberto and Dragoni, Nicola and Bucchiarone, Antonio and Mazzara, Manuel},
journal={Future Internet},
volume={11},
number={6},
pages={127},
year={2019},
publisher={Multidisciplinary Digital Publishing Institute}
}
@article{linthicum2017connecting,
title={Connecting fog and cloud computing},
author={Linthicum, David S},
journal={IEEE Cloud Computing},
volume={4},
number={2},
pages={18--20},
year={2017},
publisher={IEEE}
}
@article{shen2017block,
title={Block design-based key agreement for group data sharing in cloud computing},
author={Shen, Jian and Zhou, Tianqi and He, Debiao and Zhang, Yuexin and Sun, Xingming and Xiang, Yang},
journal={IEEE Transactions on Dependable and Secure Computing},
year={2017},
publisher={IEEE}
}
@article{shirazi2017extended,
title={The extended cloud: Review and analysis of mobile edge computing and fog from a security and resilience perspective},
author={Shirazi, Syed Noorulhassan and Gouglidis, Antonios and Farshad, Arsham and Hutchison, David},
journal={IEEE Journal on Selected Areas in Communications},
volume={35},
number={11},
pages={2586--2595},
year={2017},
publisher={IEEE}
}
@article{kolias2017ddos,
title={DDoS in the IoT: Mirai and other botnets},
author={Kolias, Constantinos and Kambourakis, Georgios and Stavrou, Angelos and Voas, Jeffrey},
journal={Computer},
volume={50},
number={7},
pages={80--84},
year={2017},
publisher={IEEE}
}
@web{fusion_analytics,
author={Microsft},
title={Advanced Multistage attack detection in Azure Sentinel}
howpublished="\url{https://docs.microsoft.com/en-us/azure/sentinel/fusion}"
}
@misc{microsoft,
author = {Microsoft},
title = {Discover and manage shadow IT in your network},
howpublished = "\url{https://docs.microsoft.com/en-us/cloud-app-security/tutorial-shadow-it}"
}
@web{microsf41,
author = {Microsoft},
title={Microsoft way of detecting threats},
howpublished="\url{https://docs.microsoft.com/en-us/azure/security-center/security-center-alerts-overview}"
}
@link{mslinks2,
author = {Microsoft},
title={Cloud Smart Alert Correlation in Azure Security Centre},
howpublished="\url{https://docs.microsoft.com/en-us/azure/security-center/security-center-alerts-cloud-smart}"
}
@link{amazon2,
author={Amazon},
title={Amazon Guard Duty},
howpublished="\url{https://aws.amazon.com/guardduty/}"
}
@link{google31,
author={Google},
title={Forsetti Intelligent Agents},
howpublished="\url{https://cloud.google.com/solutions/partners/forseti-firewall-rules-anomalies}"
}
@web{cloud33,
author={Wikipedia},
title={Sample Cloud Image},
howpublished="\url{https://en.wikipedia.org/wiki/Cloud_computing#/media/File:Cloud_computing.svg}"
}
@web{capgemini1,
author={Capgemini},
title={Anomaly detection with machine learning powered by Google cloud},
howpublished="\url{https://www.capgemini.com/resources/anomaly-detection-with-machine-learning-powered-by-google-cloud/}"
}
@web{googlelab3,
author={Google},
title={Python data science handbook K means clustering},
howpublished="\url{https://colab.research.google.com/github/jakevdp/PythonDataScienceHandbook/blob/master/notebooks/05.11-K-Means.ipynb#scrollTo=JP4_e-wZJYVW}"
}
@web{google4,
author={Google},
title={How to view vulnerabilities and threats},
howpublished="\url{
https://cloud.google.com/security-command-center/docs/how-to-view-vulnerabilities-threats#dlp
}"
}
@web{clientlibrary2,
title={Anomaly Detector Client Library for Python},
howpublished="\url{https://docs.microsoft.com/en-us/azure/cognitive-services/anomaly-detector/quickstarts/detect-data-anomalies-python-sdk}"
}
@web{microsoft3,
author={Microsoft},
title={Display Anomaly Data Points},
howpublished="\url{
https://docs.microsoft.com/en-us/azure/cognitive-services/anomaly-detector/tutorials/batch-anomaly-detection-powerbi
}"
}
@article{pannu,
author={Pannu, H.S., Liu, J.G. and Fu, S. },
title={AAD: Adaptive Anomaly Detection System for Cloud Computing Infrastructures},
}
@article{roch,
author={Roschke, S., Cheng, F. and Meinel, C.},
title={ (2009) Intrusion Detection in Cloud. Eight IEEE International Conference on
Dependable Automatic and Secure Computing, Liverpool, 729-734}
}
@article{wchen,
author={W-H. Chen, S-H. Su, and H-P. Shen,},
title={ “Application of svm and ann for
intrusion detection,” Computer Oper Res, vol. 32, no.10, pp. 2617–2634,
2005}
}
@article{dhanl,
author={Y. Dhanalakshmi, and I. Ramesh Babu},
title={“Intrusion detection using data
mining along fuzzy logic and genetic algorithms,”}
journal={International Journal
of Computer Science \& Security},
volume= {8},
issue={2},
pages= {27–32},
year={2008}
}
@web{density,
author={Daniel Chepenko},
title={A density based algorithm for outlier detection},
howpublished="\url{https://towardsdatascience.com/density-based-algorithm-for-outlier-detection-8f278d2f7983}"
}
when I get to see final pdf generated then it is as following

if you note reference number 2 is the last number in the bibliography pasted above I expected this to be last reference in the pdf generated. So I want to know how is this 1,2,3,4 generated, which thing in my bibliography is getting priority
@Techreport,@article,@web,@link,@misc,
these are the tags I used I did it at random what ever came to my mind. Is there a systematic nomencleature for this.
I am using a template which I downloaded from here https://www.overleaf.com/latex/templates/eusflat-2019-template/jmqvcrhkqhgx I downloaded in my local machine and I am using it.
There is a file with name EUSFLAT2019_template.bbl I see following in it
\begin{thebibliography}{10}
\expandafter\ifx\csname url\endcsname\relax
\def\url#1{\texttt{#1}}\fi
\expandafter\ifx\csname urlprefix\endcsname\relax\def\urlprefix{URL }\fi
then I see a lot of \bibitem entries in it. Then I have BIBeusflat2019.bib in which I have all these things in format
@web{density,
author={Daniel Chepenko},
title={A density based algorithm for outlier detection},
howpublished="\url{https://towardsdatascience.com/density-based-algorithm-for-outlier-detection-8f278d2f7983}"
}

\setbox0=\hbox{\cite{aaa,bbb,...}}, whereaaa,bbb,...is the preferred order in which you would like the future references to occur. – Steven B. Segletes Mar 16 '20 at 14:51