Cybersecurity involves protecting computers, servers, mobile devices, electronic systems, networks, and data from malicious attacks. It's also known as information technology security or electronic information security. The field is categorized into several common branches:

1. Network Security: The practice of securing a computer network from intruders, whether targeted attackers or opportunistic malware.
2. Application Security: Focuses on keeping software and devices free of threats. A compromised application could provide access to the data its designed to protect. Security begins during the design phase, well before a program or device is deployed.
3. Information Security: Protects the integrity and privacy of data, both in storage and in transit.
4. Operational Security: Includes the processes and decisions for handling and protecting data assets. The permissions users have when accessing a network and the procedures that determine how and where data may be stored or shared all fall under this umbrella.
5. Disaster Recovery and Business Continuity: Defines how an organization responds to a cyber-security incident or any other event that causes the loss of operations or data. Disaster recovery policies dictate how the organization restores its operations and information to return to the same operating capacity as before the event. Business continuity is the plan the organization falls back on while trying to operate without certain resources.
6. End-user Education: Addresses the most unpredictable cyber-security factor: people. Anyone can accidentally introduce a virus to an otherwise secure system by failing to follow good security practices. Teaching users to delete suspicious email attachments, not plug in unidentified USB drives, and various other important lessons is vital for the security of any organization.

The importance of cybersecurity continues to grow, driven by the increasing reliance on computer systems, the Internet, wireless network standards like Bluetooth and Wi-Fi, and the growth of "smart" devices, including smartphones, televisions, and the various devices that constitute the Internet of Things (IoT).

Threats: Cyber threats can come from any level and can involve theft of financial information, governmental information, or the disruption of national infrastructure. Furthermore, sophisticated cyber criminals and nation-states exploit vulnerabilities to steal information and money. They can also aim to disrupt, destroy, or threaten the delivery of essential services.

Techniques: A variety of methods are used in cybersecurity. Encryption is one, which involves encoding information in such a way that only authorized parties can access it. Antivirus and anti-malware solutions are continually evolving to respond to the myriad of threats. Behavioral analytics are used to detect patterns that could suggest a threat. AI and machine learning can replicate or predict behavior and identify potential breaches before they occur.

Challenges: The field of cybersecurity is challenging due to the volume and sophistication of attackers and the significant amount of data that is handled. Practitioners need to stay ahead of threats by updating their practices frequently, adding new defense mechanisms, and ensuring that all elements of cybersecurity are maintained.

Given the scope of cybersecurity, developing a robust approach involves investment in technology, processes, and people. It is not only about protecting data but also about ensuring the continuity and resilience of business operations.