Trouble with Salesforce Interview Questions

[sheen8]

I am currently trying to prepare for a Salesforce interview job and I am having some trouble understanding some of the questions. I am a beginner and some of the terminology and concepts are a bit overwhelming for me. For example, I am having difficulty understanding the following code:

public class AccountController { 
 public static void deleteAccount(Id accountId) { 
  Account account = [SELECT Id, Name FROM Account WHERE Id = :accountId]; 
  delete account; 
 } 
}  

Can someone please explain what this code does? Any help or advice would be greatly appreciated.

Thank you.