Intangible assets refer to the identifiable non monetary assets owned or controlled by enterprises without physical form. Compared with other assets, intangible assets have three main characteristics: no physical form; recognizable; non monetary long-term assets. Intangible assets are non monetary assets, which can bring economic benefits to the enterprise in multiple accounting periods. The service life of intangible assets is more than one year, and its value will be amortised in each benefit period.