Your banks will never ask you for personal information by email. They will also never give you a link to click on to log in. If you receive emails that ask for this, use a direct link you already have. These are usually on letters and statements from your bank.
Some of these emails will say your account has been hacked, some money has gone missing or something along these lines. They will encourage you to click on a link in their email which will take you to a special website which will look like your bank’s website but will be owned by the scammers. These emails are known as phishing emails. They will ask you to put in your username and password, which they will then record. You will be redirected to your actual bank and you will probably not know what has happened until your real bank contacts you by phone or letter.
The way to avoid this is never to click on any link in an email that appears to be from your bank but to go and have a look at your bank’s website directly.