In this era, human activities have seen a shift and our majority activities including social, cultural,economic and even governmental and NGOs are being done in the cyberspace, especially during andafter the crisis of corona pandemic. Due to this shift in communication culture, many individuals andorganizations including governments have to face cyber-attacks. Due to heavy reliance ontechnology and little awareness, defending against cyber-attacks is very challenging. Cyber attacksare usually conducted with the goal of harming an organization or individual financially or theseattacks may also be motivated for political or military purposes. Viruses, malwares, ransomwares,denial-of-service and phishing attacks are some of the examples. To protect themselves,organizations employ variety of strategies to mitigate or prevent the threat of these attacks. Toprevent and mitigate cyber-attacks, researchers and professionals have devised a number oftechniques. This paper is written to thoroughly study and analyze these various approaches andproposed cybersecurity standards, and also to look into the problems, limitations and strengths ofthese techniques. Fundamental concepts of cyber-attacks and cyber security are discussed alongwith the current advancements and upcoming trends in security of cyber space. Such acomprehensive review paper would be highly beneficial.