Let me paint this picture more clearly.
In every instance that we visit a website or download whatsapp number list a movie, details of that visit gets stored in our computer. Because they are placed in folders that are hidden from us, we really have no way of finding which files are included or how to delete them.
For instance, when we

write down application letters containing personal information, we may delete them when we are through with them. We can even go further as to remove them from the recycle bin. But especially when you are sharing the computer with other people, they can still retrieve that file from your hard disk.
I know that these things may be really
scary but the solution is quite simple. All that you have to do is to install an evidence eraser software. In a nutshell, what an evidence eraser foes is to scan your computer for unwanted files that you may have accumulated whether consciously or subconsciously.