When you use a computer program, you might give it information to work with, like a password or a name. The program will expect this information to be a certain length, but if you give it too much information, it can cause a problem called a buffer overflow.
Think of a buffer as a container that can only hold a certain amount of information. If you try to put more information in the container than it can hold, the extra information will spill out and cause a mess.
Similarly, when you give a program more information than it can handle, the extra information will overflow and start to overwrite other parts of the program’s memory. This can cause the program to crash or behave in unexpected ways.
So, if you give a program a string (like a name or a password) that is too long, it can cause a buffer overflow and potentially cause the program to malfunction.