You should always be wary of its secrecy, as someone can use it to wipe the data of any device from anywhere. Anyone with basic knowledge and access to your Gmail ID and password can do this. Along with wiping data or locking the device, IMEI tracking can also facilitate other illegal activities.
The most common use of the IMEI number occurs when you lose your device or, even worse, when it gets stolen.
You should always have this information to track IMEI number and find the lost phone. There are many tracking apps & websites, but only some of those are legit. Police, other Defence agencies, mobile companies, etc. have reliable IMEI tracking apps and software. They mainly do it to track the criminals or phone thief, when you lodge a complaint about the stolen phone or other devices.
Ways to Know your IMEI Number
First, the box of the mobile phone always comes with the IMEI number on it. If you have a dual SIM phone, two IMEI numbers should be there.
If you have already lost the phone, log in to the Gmail account that was on your phone. Then go to the devices, and there you can find it to track IMEI number.
Dial *#06# from your mobile device, and the screen will display the IMEI number. You should keep it safe with you by noting it down or taking a screenshot for future use.
Concluding Thoughts
These points should have apprised you of the processes to find the IMEI number. A good tracking app can readily track your device and help you get it back.