Chad Fowler's "professional services barrier" label https://books.google.ie/books?id=ig9QDwAAQBAJ&pg=PT48&lpg=PT48&dq=%22the+professional+services+barrier%22&so

Chad Fowler's "professional services barrier" label https://books.google.ie/books?id=ig9QDwAAQBAJ&pg=PT48&lpg=PT48&dq=%22the+professional+services+barrier%22&source=bl&ots=upS7baIPe5&sig=YoLMgQr0X_ieSaNZI3hNX_bgrRQ&hl=en&sa=X&ved=2ahUKEwiG3Zrl7YbfAhWLSRUIHUH5AhYQ6AEwAHoECAQQAQ#v=onepage&q=%22the%20professional%20services%20barrier%22&f=false https://books.google.ie/books?id=ig9QDwAAQBAJ&pg=PT48&lpg=PT... is a fair stab at explaining some of the difference. Which isn't to say that the distinction is really black and white, especially for non-programmers or people who don't have a lot of time to invest in a particular kind of tool.