Collecting, storing and processing data

Collecting data means identifying data that already exists, or gathering new data. A school might move its records from a paper register to a spreadsheet, save them as a CSV (comma-separated values) file, or build new software with a database.

Data is generated continuously all around us: by hospitals, shopping malls, banks and social media. International bodies such as the World Bank and the IMF collect economic data from many countries.

Storing data needs storage devices: hard disk drives (HDD), solid state drives (SSD), CDs and DVDs, tape drives, pen drives and memory cards. As data grows, simple files become hard to manage, and a database management system (DBMS) is used instead (see the next chapter).

Processing data turns raw data into useful information. It follows a cycle:

• Input: collection of data, preparation (checking and organising it), and entry into the computer.
• Processing: storing, retrieving, classifying and updating the data.
• Output: the results, such as reports, charts or results.

Example: an ATM withdrawal. Input: the card number, account, PIN and the amount. Processing: the bank checks the PIN and the balance, deducts the amount, and counts out notes. Output: the currency notes and a printed slip. Online admit cards and train ticket booking work the same way.