Algorithms are ubiquitous in the contemporary technological world, and they ultimately consist of finite sequences of instructions used to accomplish tasks with necessary input values. This book analyses the top performing algorithms in areas as diverse as Big Data, Artificial Intelligence, Optimization Techniques and Cloud & Cyber Security Systems in order to explore their power and limitations. Algorithms play a vital role in all sciences, especially in Computer Science. We are always in search of efficient algorithms that give the results in less amount of time and that consume less space for large input size. Cybersecurity and Big Data are two prominent areas of Computer Science, where the role of algorithms is vital. Algorithms provide the best security mechanism to protect the data from all types of attacks. There are several types of attacks such as threats to data safety, data security, and on the mechanisms to store and retrieve the data. Optimization is a common term used almost everywhere, including our daily life. This book comprises chapters on the study of different algorithms used in cybersecurity and Big Data, and also puts light on optimization methods used in Computer Science. A comparative study of different algorithms is also provided. This book is helpful to students, especially for those who work in areas of cybersecurity and Big Data.