What is the point of putting local? instead of no local

Since after you put an end you can't use local what is the point

like for example

local part = game.workspace.part
end

--cannot use anymore


--new script
part = game.workspace.part
end
part.BrickColor = BrickColor.new("Lavender")
--I dont get why people use local in some of the scripts

Here's a link to an page about Scopes Anyway's I don't remember all the reasons but here's an example why local variables might work better.

This works but however if I were to do this

local Function Test()
local Test = "Test"
wait(1)
end

local Function Test2()
local Test = "Test"
end

But if I do this then Test get's replaced with Test2.

local Function Test()
Test = "Test"
wait(1)
print(Test)
end

local Function Test_2()
Test = "Test2"
print(Test)
end