When to use :Waitforchild()

[ZEZ3Z2 (ZeZe)]

Hello everybody!
I want to know when to use the :WaitForChild() statement.
My problem is that I do not know when really use it. I know that you have to use it when you want to wait for an object you know will exist but then should I not make everything:WaitForChild() if for example, a player with a bad internet connection is playing my game?
I have tried to look for answers on the forum, hidden-devs discord server, and asked chatGPT but I seem not quite to understand it.

[happya_x (Happya)]

i think client scripts run after the game loads, so all of the objects on the client will be loaded when the client script runs and internet connection doesnt matter

you should only use waitforchild when you have to like when waiting for character body parts to load in after they respawn

[Ziffixture (Ziffix)]

https://create.roblox.com/docs/reference/engine/classes/Instance#WaitForChild

[BluackHDI (BlackingSplash)]

Many use cases.

• Example: let’s say I wanna receive a variable 5 seconds after I announce it for whatever reason. Let’s say there is a ScreenGui inside the script: ```

local variable = script:WaitForChild("ScreenGui", 5) -- 5 seconds before we receive it.

• It can also be used for variables that will exist after the game runs.
  Script 1:

local player = game.Players.LocalPlayer
local value = Instance.new("NumberValue", player)

Script 2:

local numberV = game.Players.LocalPlayer:WaitForChld("Value")