We can say that Vishing is the same as Phishing, except that instead of luring customers via e-mail, the scammers use Voice over IP or a direct telephone call to gain access to your personal details. Please check How to avoid Phishing & Vishing here.
To make it simple we will explain the same with an example like, you might get a call from someone claiming to be an employee of the Bank you have your account in. Citing reasons like unauthorized transactions or standard safety procedures, they might ask you to share your personal and financial details so that they can verify and secure your account.
Once you share your details, they use it to gain access to your account. It is difficult to book people involved in vishing and bring them to justice as it is conducted by voice process.
How to Avoid Vishing?
Such scams are often generated from across borders, so it is difficult for law enforcement agencies to apprehend such perpetuators of the crime. Make sure that you do not entertain the message or calls that seem suspicious. You should refrain from entertaining any such calls and ensure that you do not share any kinds of details. Remember that your Bank will never make such a call to you. If anything happens just report to your bank.