An exploit is a program, malware or hacking technique designed to take advantage of any and all vulnerabilities present in a system in order to destroy or cripple it.
In other words, it means that you can launch an exploit if the target system is vulnerable.
From there, you can get administrator or root access on the target system, thus fully compromising it.
Penetration Testing can also make use of exploits in order to analyze and assess the integrity of a given system, which incidentally can be accomplished with the use of SecPoints own Penetrator hardware.
The SecPoint Penetrator is a dependable pen test device you can use to check, double-check, and guarantee the strength or weakness of your system security.
It's the skeleton key or lock pick that enables intruders, hackers, online outlaws, cyber criminals, virtual villains, and net never-do-wells to compromise an wreak havoc on your website host, office network, or individual computers connected to the Internet.
As a verb, to "exploit" in computer system terms means to successfully take advantage of a vulnerability found in your system.
Many crackers are quite updated (or even manufacture) a multitude of exploits, the most famous of which are viruses such as the Melissa virus, Nimda, vandal, and Bugbear.
Hackers also help each other by keeping tabs with one another in regards to recently discovered vulnerabilities and the exploits that one can use to exploit them.
At any rate, to reiterate, you need the help of a pen testing programs or equipment like the SecPoint Penetrator in order to find vulnerabilities and the possible ways to exploit them before malicious black hat hackers do so that these weaknesses can be patched by software developers post-haste.