Data communication is the transfer of information from one person to another. It is a way of reaching others by transmitting ideas/facts/thoughts/feelings/attitudes and values. Data communication, however, is somewhat different from communication. Data communication is specific in the context of the Computer-based Management Information System. Data connection consists of
• Data processing
• Data transmission
Data is unstructured raw facts in isolation to be used as the raw material of/for the information system. Data is also the glue or mortar of the information system. Data could be expressed in numeric, alphabetic, alphanumeric, special characters, images, symbols or even voice. The various forms of data expressions are understood by the computer as strings of “0” or “1”. The computer works with electrical pulse off or on, which state is equivalent to “Off’ and “On” representing “0” and “1”. The “0” and “1” are known as Binary Digits or BITS. The computer uses strings made in the combination of “zeros” and “ones” to move, store and compute the data.
Data organization/sequence The data is moved, stored and computed in the unit of bytes. One byte represents one character. The byte is made of eight bits. The data is structured for processing in a certain sequence and is ultimately stored in the file.
• The Bits form a Byte.
• The Byte represents Character.
• Some Characters forms a Field.
• Fields constitute a Record.
• Records constitute a Block.
• Blocks constitute a File.
• Files constitute a Database.
Data processing and transactions What data processing does is transaction processing. If there is no transaction, there would not be any data/document generated and hence no need for data processing. Let us, therefore, remember that “transaction is a fundamental organizational function.” Business is conducted through business transactions, which are recorded systematically. A sales order accepted by a salesperson, a purchase order issued, reservation, money being deposited in or withdrawn from the bank are all examples of business transactions, which are recorded and then processed. If there are no transactions, there would be no data/document, and hence there would be no need for data processing either. Transaction Processing, The transaction processing system, is vital for organizational operations. Without it, bills would not be paid; purchase orders would not be issued, sales orders would not be placed, reservations would not be made. However, before processing a transaction, the relative data item has to be checked, verified and found correct/acceptable as regards to its quality specification. This process is called data validation. This operation is effected by using a set of computer software programs, known as the validation programs, where specific data validation tests are applied to the data items.