[Ammako]

k, v are the values being iterated through in your for loop (k = key, v = value)

You use those variables in the loop and it "increments" through to the next key/value every time it loops through.

Example usage:

local function contains(table, element)
    for _, value in pairs(table) do
        if value == element then
            return true
        end
    end
    return false
end