What do descendants and ancestors mean in the real world?

A descendant is a direct or indirect child. A good example is you are their grandparents. You are not directly their children but you're their descendant. But you're still your parents (mom and dad) descendants.

And they are your ancestors. The only functions I know of is GetChildren, GetDescendats, IsAncestorOf, IsDescendantOf.

For some reason roblox doesn't provide a GetAncestors function.

Eh just for fun I wrote this.

local function get_ancestors(instance)
    local instance_parent = instance.Parent
    local ancestors = { instance_parent }

    while instance_parent do
        instance_parent = instance_parent.Parent
        table.insert(ancestors, instance_parent)
    end
    return ancestors
end