The field of cybersecurity has undergone significant changes from the 1990s to the present day, driven by the evolution of technology and the increase in cyber threats. Some of the key changes in cybersecurity during this period include:

1. Increased Threat Landscape: Cyber threats have become more sophisticated, and new types of threats such as advanced persistent threats (APTs) and zero-day exploits have emerged.
2. Advancements in Technology: The rise of cloud computing, mobile devices, and the Internet of Things (IoT) has significantly expanded the attack surface, creating new vulnerabilities and threats.
3. Regulatory Compliance: Governments around the world have introduced laws and regulations to protect individuals and organizations from cyber threats.
4. Cybersecurity Awareness: Individuals and organizations have become more aware of the need for cybersecurity, and there is now greater awareness and training available to help individuals and organizations protect themselves against cyber threats.
5. Cybersecurity as a Business: Cybersecurity has become a major industry, with companies investing heavily in cybersecurity products and services to protect their assets and data.

To protect their assets, companies should take a multi-layered approach to cybersecurity, which includes implementing the following measures:

1. Risk Assessment: Companies should conduct regular risk assessments to identify potential vulnerabilities and threats.
2. Security Policies: Companies should establish and enforce security policies and procedures to minimize the risk of cyber attacks.
3. Employee Training: Companies should provide regular cybersecurity training to employees to raise awareness and prevent human error.
4. Network Segmentation: Companies should implement network segmentation to limit the impact of any potential breaches.
5. Data Backup and Recovery: Companies should regularly backup their data and implement a robust data recovery plan in case of a breach or data loss.
6. Advanced Threat Detection: Companies should use advanced threat detection technologies like behavior-based detection and machine learning algorithms to quickly identify and respond to potential threats.

Overall, the changes in cybersecurity from 1990 to the present day reflect the evolution of technology and the increasing reliance on the internet. To stay ahead of the ever-evolving cyber threat landscape, companies must continually adapt and invest in cybersecurity measures to protect their assets and data.