In the expansive universe of cybersecurity, Penetration testing, simply referred to as 'Pen testing,' stands as a critical tool for organizations aspiring to safeguard their systems. It illuminates cyber vulnerabilities and arms businesses with the valuable insight of understanding their systems from an attacker perspective.

With soaring dependency on digital spaces, cyber threats are continually evolving, mandating businesses to aim beyond mere prevention strategies. This is where the concept of 'penetration', a proactive approach, becomes instrumental in enhancing the cybersecurity stance.

What Is Penetration Testing?

Penetration testing approximates a legalized hacking attempt, subjected to a system, network, or web application, aiming to exploit possible vulnerabilities. Relatively than waiting for an incident, organizations perform intentional attacks on their infrastructure to identify potential weaknesses before it's too late.

Assessing the Value of Penetration Testing

Understanding how 'penetration' testing adds value to cybersecurity measures is essential. Being a proactive method, it helps companies discern tech susceptibilities, preventing potential losses due to cyber-attacks, and ensuring regulatory compliance, thus strengthening customer trust.

The Structure of Penetration Testing

No 'penetration' test is bereft of a structured technique. Broadly, the process can be divided into five stages - Planning, Scanning, Gaining Access, Maintaining Access and Analysis.

Stage 1: Planning

The initial stage of any 'penetration' test includes defining the scope and goals, gathering information about the target systems, and identifying methods to be employed. It's a stage of strategizing the entire Penetration testing process.

Stage 2: Scanning

Scanning is about understanding how the target application or system will respond to various intrusion attempts. It generally involves manual or automated testing to scan systems and identify weaknesses.

Stage 3: Gaining Access

This stage in 'penetration' testing involves exploiting the vulnerabilities identified in the previous stage. Techniques like cross-site scripting, SQL injections, or backdoors are used to ascertain the damage they can cause.

Stage 4: Maintaining Access

This stage tests whether the vulnerability can be used to achieve prolonged presence in the exploited system–a tactic often used by malicious attackers to gather as much data as possible.

Stage 5: Analysis

The final stage involves collating data from 'penetration' tests to create comprehensive documentation detailing the vulnerabilities found, data exploited, and the length of time the tester could remain in the system undetected.

Common Types of Penetration Testing

Basic Penetration testing categories encompass Network testing, Web Application testing, Social engineering testing, Physical Penetration testing and Targeted testing among others. Each category emphasizes different aspects of a business’s security posture and offers insight into different potential vulnerabilities.

Best Tools for Penetration Testing

'Penetration' testing is greatly aided by a range of sophisticated tools such as Metasploit–a powerful testing tool that creates simulating attacks, Wireshark–a network protocol analyzer helping in traffic analysis, and tools like Nessus and Nmap that help in scanning and identifying vulnerabilities, respectively.

The Future of Penetration Testing

As technology and cybersecurity threats continue to evolve, 'penetration' testing too will undergo evolution. The foreseeable future is expected to see growth in Automated Penetration testing, inclusion of AI and Machine learning in Pen-Test tools, and a heightened focus on IoT testing.

In conclusion, 'penetration' testing remains not simply an option but a necessity in the contemporary cybersecurity landscape. By adopting a proactive approach to identify vulnerabilities and simulate real-world attacks, businesses can significantly fortify their security infrastructure. With the ever-expanding digital sphere and escalating cyber threats, the pertinence of 'penetration' techniques in testing only promises to become more significant in the future, aiding businesses in augmenting their cybersecurity measures.