Can anyone let me know how to prevent others from using my ps3 console by using a password,just like a PC does.
You can't lock out a user from your local account, but here's a few tricks I used to keep people from using my PS3
Protecting your Online Account
First, and easiest, uncheck the option to 'Remember Password' for your PSN (online) account. this will stop people from being able to play as you and ruin your reputation/stats online.
Password Prompt when Starting Games*
Next, you want to go into Settings->Security Settings->Parental Control It will ask you for a passcode, enter one (make sure you remember it).
Set the parental control level to 1 (the strictest) and when prompted, check the box that says "Restrict Starting a game with no Parental Control Settings" and click OK.
Password Prompt when Starting Internet Browser
If you want to restrict access to the Internet browser as well, go back to Parental Control and choose Internet Browser Start Control.
Enter your password, and change the setting to On
Password Prompt when attempting to playback DVDs/BluRay disks
You can even restrict access to DVD & Blu Ray disks as well, these options are under Security Settings again, this time choose DVD - Parental Control and BD Parental Control respectively.
Enter your password, and again change the setting to On
* : This will restrict games on discs as well as games downloaded from the Playstation Store.