Well kiddo, have you ever played the game 'hangman'? In this game, we have to guess a word by guessing one letter at a time, and with each wrong guess, the game adds a body part to a hanging man character.
Now, let's think about how many guesses we might need to make in order to guess a word correctly, if we get a certain number of wrong guesses before the man gets "hanged."
The Gilbert-Varshamov bound is a mathy way of calculating the maximum number of errors or guesses we can make before we won't be able to guess the word correctly. This is helpful for coding and computer science, because we can use this bound to make sure we don't make too many errors when transmitting information over a noisy channel (like a bad internet connection).
So, to summarize: the Gilbert-Varshamov bound is a way of figuring out how many errors we can tolerate when trying to guess a word or send information over a noisy channel. It's like the hangman game, but with math!