I can talk about vulnerabilities a lot because is a complex word.
If you look for the definition in http://www.thefreedictionary.com/
- a. Susceptible to physical or emotional injury.
b. Susceptible to attack: “We are vulnerable both by water and land, without either fleet or army” (Alexander Hamilton).
c. Open to censure or criticism; assailable.
a. Liable to succumb, as to persuasion or temptation.
b. Games In a position to receive greater penalties or bonuses in a hand of bridge. In a rubber, used of the pair of players who score 100 points toward game.
Now that we know the meaning of the word, I´m going to talk about it.
If you talk about computing you should talk about vulnerabilities. Both words are complementaries. A computer have vulnerabilities and vulnerabilities are in computers.
* You are the best developer in the world and your programs are the safest and the best. A person installs your application but he has forgotten to put a password in the admin console. This is a vulnerability. Is not your fault, but is a vulnerability.
* You are a new developer without any experience. your application can execute arbitrary code in a remote machine because your code have a security hole. This is another vulnerability.
If you talk about life(no computers).
*You are in a restaurant and you want to pay with your credit card. Waiter takes your cc and you lost sight of him. He can copy your credit card, steal it or simply lose it. This is another one 😉
Then, be careful with your private data or with the tools that you are handling.