ruby-on-rails - Railsのaasm列の意味は何ですか

Question

私はレールが初めてで、このコードを持つ1つのプロジェクトを行っています

 aasm_column :status
  aasm do
    state :unregistered, initial: true
    state :pending, enter: :enter_pending_state
    state :activated, enter: :enter_activated_state
    state :disabled

    event :register do
      transitions from: :unregistered, to: :pending, guard: :valid?
    end

    event :activate do
      transitions from: [ :unregistered, :pending ], to: :activated
      transitions from: :pending, to: :activated, guard: :valid?
    end

    event :disable do
      transitions from: [ :pending, :activated ], to: :disabled, guard: :valid?
    end

    event :enable do
      transitions from: :disabled, to: :activated, guard: Proc.new { |u| u.activation_code.blank? && u.valid? }
      transitions from: :disabled, to: :pending, guard: Proc.new { |u| !u.activation_code.blank? && u.valid? }
    end
  end

before_create :enter_pending_state, if: Proc.new{|u|  u.pending? }

aasm_columnは何を意味し、これを行うための陳腐さは何ですか