Will for i,v in pairs be useful in basic rblx games?

This is a special form of iteration designed to traverse through an array. The pairs() function will push the current index point, and element within the table at the respective point of iteration into two variables, i and v. These define Index and Value. These two variables can be named whatever you like, or ignored if not needed via using the special character _.

This is highly useful as it can allow us to perform multiple tasks on tones of Instances with barely any lines of code—or process a lot of information quickly—this is something you'll find yourself needing to do, or doing in several basic programs.

Let's take a look at a basic application, killing everyone in-game:

local Players = game:GetService("Players"):GetPlayers() --// Gives an array.

for _,Player in pairs(Players) do
    if (Player.Character) then
        local Humanoid = Player.Character:FindFirstChildOfClass("Humanoid")
        if (Humanoid) then
            Humanoid:TakeDamage(Humanoid.Health)
        end
    end
end