It’s no exaggeration to say that computers have changed our lives in significant ways. The pace of change in sectors as varied as health, finance, engineering, governance, and education (among others) has been so fast that we find it difficult to keep up. The transformation is not restricted to our professional and official lives, either. In the personal sphere too, computers – or more correctly, digital technologies – have brought about changes in our patterns of leisure, information seeking behaviours, what media we consume and how, and the way we maintain our relationships. Even those of us who are not teaching or studying computer science need a measure of digital literacy to navigate the world these days. Almost every discipline makes use of computers in some way – to process and present data, to retrieve and manage information, to create and manipulate models, etc.

Beyond the use of the computer as a tool to enhance productivity, we are also now entering into an era where we are being asked to approach tasks in a programmatic manner – what some people call “algorithmic thinking”. This is particularly useful in activities that can be broken down into systematic units, and thought through in a logical, step-by-step manner. Computers have certainly pushed us to asking questions differently (for instance, using search terms in strategic ways), and asking different questions. Some scholars say that these machines have allowed us to better understand human thinking and behaviour. The early computers were modeled on our knowledge of the human brain, while now we use computer intelligence (machine learning) to explore what it means to be human!

Carrying on our tradition of bringing our readers a subject-focused double issue every summer, Teacher Plus this year has put together a collection of articles on computer science, written by our large network of contributors – teachers, computer scientists turned educators, and a variety of “thinking others”. As always, it was a challenge to squeeze all of a subject into 100-odd pages, but we’ve tried to represent a broad swathe of topics that will be of interest to teachers of computer science as well as others who use computers in their everyday work. And as always, we have attempted to offer a balance of the practical, the theoretical, and the informative.

No doubt there are many aspects of computer science that we have not been able to include, but the articles in this collection should offer a glimpse of the wide space of the discipline and its applications. Do let us know what you think!