Anomaly detection is an important element in the domain of security. As a result, we undertook a literature review on ML algorithms that identify abnormalities. In this paper, we are presenting a review of the 101 research articles describing ML techniques for anomaly detection published between 2015 - 2022.The goal of this paper is to review research papers that have used machine learning to develop anomaly detection algorithmThe forms of anomaly detection examined in this study include system log anomaly detection, network anomaly detection, cloud-based anomaly detection, and anomaly detection in the medical profession. After assessing the selected research articles, we present more than 10 applications of anomaly detection. Also, we have shared a range of datasets used in anomaly detection research, in addition to revealing 30+ new ML models employed in anomaly detection. We have discovered 55 new datasets for anomaly detection. We've noticed that the majority of researchers utilize real-life datasets and an unsupervised learning technique to detect anomalies. Many ML methods may be applied in this subject, so we present a summary of all work done in the previous six years. Keywords Intrusion detection, Artificial intelligence, Anomaly detection, security, Machine learning.