This is especially true of musicians that may want to attach all sorts of audio recording equipment to the computer.
Another reason is that the internal sound card may only have a 3⁄4 jack and they want to have the option to output to a coaxial jack or an optical jack. Firstly, customers may not be happy with the quality of the internal sound card they have so they want to replace it. There are a number of reasons why an external audio card may be needed. An external audio card helps to process data into audio to supply output devices like headphones and speakers.
