An IT service company's primary function is to provide businesses with crucial technological solutions. This ranges from vulnerability testing to cyber security services, and even to supplying and managing cloud computing services.

One of the key offerings from IT service companies is the vulnerability testing service. This service probes a business's system for weaknesses that would enable external threats to breach the defenses. Using a combination of both manual and automated systems, these tests try to detect system vulnerabilities as a preemptive measure for security enforcement.

On discussing cyber security services, IT companies pledge the shielding of business applications, databases, and networks against heterogeneous cyber threats. They provide comprehensive security measures, including defences against malware and viruses, intrusion detection systems, firewalls, and crisis response plans. IT service companies strive to stay up to date with developing cyber threat landscapes, ensuring their business customer's digital resources are well protected.

Finally, let's delve into the world of cloud computing services. These services essentially allow businesses to save and control their data over the internet instead of an on-premises server. This is advantageous as it gives increased collaboration, limitless scalability, cost savings and flexible operations. As a cloud Cloud Computing Services service provider, IT companies handle the job of managing this remote data storage system, providing high-quality availability and security for a business's valuable data.

In wrapping up, it is evident that the role of an IT service company is diverse, offering a wide array of services including but not limited to vulnerability testing, cyber security, and cloud computing services. All of these services play a critical role in maintaining the integrity and efficiency of a corporation's digital infrastructure. Thus, engaging with a competent IT service company can safeguard a company's digital ecosystem and facilitate efficient operations.