How come this script can attack whoever closet to it? can someone explain

local myHuman = script.Parent:WaitForChild("Humanoid")
local myRoot = script.Parent:WaitForChild("HumanoidRootPart")

local attackCool = true
local clone = script.Parent:Clone()





function checkDist(target)
    return (myRoot.Position - target.Position).Magnitude
end

function getUnstuck()
    myHuman:Move(Vector3.new(math.random(-1,1),0,math.random(-1,1)))
    myHuman.Jump = true
    wait(0.5)
end



function findTarget()
    print("Hello")
    local dist = 50
    local target = nil
    for i,v in ipairs(workspace:GetChildren()) do
        local human = v:FindFirstChild("Humanoid")
        local torso = v:FindFirstChild("Torso") or v:FindFirstChild("HumanoidRootPart")
        if human and torso and v.Name ~= script.Parent.Name then
            if checkDist(torso) < dist and human.Health > 0 then
                target = torso
                dist = checkDist(torso)

            end
        end
    end
    return target
end




function attack(target)
    if attackCool == true then
        attackCool = false



        target.Parent.Humanoid:TakeDamage(10)

        spawn(function() wait(0.5) attackCool = true end)
    end
end



function main()
    local target = findTarget()
    if target then
        if checkDist(target) > 6000 then
            getUnstuck()
        else
            attack(target)
        end
    else
        getUnstuck()
    end
end

while wait() do
    if myHuman.Health > 0 then
        main()
    else
        break
    end
end







function attack(target)
    if attackCool == true then
        attackCool = false



        target.Parent.Humanoid:TakeDamage(100)

        spawn(function() wait(0.5) attackCool = true end)
    end
end