In Ruby what's the difference between doing @name or self.name ?

Question

class Person
attr_accessor :name, :age
def initialize(name, age)
@name = name
@age = age
end
def change(n, a)
self.name = n
@age = a
end
end

p = Person.new("David", 28)
p.change("Bob", 42)
puts p.name
puts p.age

#Output
Bob
42