why do you need parameters without function??

i dont mean that parameters are useless but sometimes i see scripts that have parameters for no reason :

game.workspace.Part.Touched:Connect(function(hit)
       print("hit") ---- but what is hit?
end)

i only know that parameters can be used like this :

function kill(PlayerName)
      local player = game.workspace:WaitForChild(PlayerName)
      Player:FindFirstChild("HumanoidRootPart"):Destroy()
end

kill("leoonardo101max1")

if you know pls answer this