Sometimes people say “I want the password on my new account to be..” and it turns out they’re using that password for everything.
So that’s convenient, they only have to remember one thing for all their accounts. But it’s very unsafe. It means that if the badguys get this password, they will have access to all those accounts: email, bank, serious stuff. Sometimes the badguys can get your password without you doing anything wrong. For example, linked-in had a data breach a few years ago which gave out thousands of their users’ passwords, through no fault of the users. (It’s not only linked-in: plenty of other sites and services have had similar problems.)
“But I can’t remember 50 different passwords. And I’m not supposed to write it down, huh?”
True, a note stuck on the side of the computer is not safe. But writing it down in a little black book that’s stored away from the computer is pretty good. Certainly less of a risk than having all passwords the same.
Better still is a password manager program. (Also called a password minder or password safe.) This is a program you install on your PC (or phone or whatever) which stores passwords safely: the only password you have to remember is the one to open the password minder. After that, things are good: when you need to get a password from it, you can cut&paste from the password minder to whatever site or app needs it. You rarely have to manually type the passwords, or even see them. As a bonus, most password minders have space to store private notes, extra account numbers or whatever you like, for each account.
With a password minder, your passwords can be long, random and all different. That’s what you want!
For Windows, I’ve been using the Keepasspassword minder.
For i-devices, 1password seems to be popular.
On my Android phone I use PasswdSafe
Here’s a list of password managers
Another day: what makes the password itself safe or unsafe? That’s also important.