Hospitals generate an immense amount of data, probably more data per dollar than any other type of organization. Health care informatics is the field that studies this subject.
There are two main ways a file can be organized:
A sequential file works like a reel of tape. (In fact, sequential files are often stored on reels of magnetic tape.) Data in a sequential file are processed in order, starting with the first item, the processing the second, then the third and so on. To reach data in the middle of the file you must go through all the data that preceeds it.
A random access file works like a sampler box of chocolate. You can access a particular item by going directly to it. Data in a random acess file may be accessed in any order. To read data in the middle of the file you can go directly to it. Random access files are sometimes called direct access files.
You might think that all files should be random access. But random access files are much more difficult to implement and to process. They are expensive in computer time and resources. However, they are convenient for the users of a program. For example, a corporation can easily answer telephone queries from a customer if it can go directly to the customer's records.
Are programs stored in files?