Some might say that technical books, in the form that is printed on dead trees, have lost their raison d’être in the connected world we’re living in. To some extent they are right, there are many cases where it is better to look up the latest information online than to confide to a dusty old reference manual. In other cases a proper book will serve you much better than an online resource.

For once, the quality level that has to be met in order to get a technical book published is just so much higher than anything posted online. If you buy a technical book you can be pretty sure that the author is an expert in his field and that and least one, in many cases several, other experts have been involved and given their input and approval.
Secondly, with a book you have all information collected in one place, usually nicely structured and with a comprehensive index at the back. I often find it just as easy to look up something in a book than it is to search for it online and in many cases the descriptions and examples in the books are much more educational which helps with the understanding on why things work as they do and not just how they work.
An argument you some times hear against buying technical books is that ”technology changes so fast that your books will be out of date before you have finished reading them”. In some cases this is true, in many cases not. The foundations on which most of the new technology is built upon have not changed in decades. Take the major programming paradigms as an example. Procedural, object oriented, and functional programming were all invented in the 50’s and 60’s and the core concepts are still the same. Hence, learning the core concepts is useful and will stay useful, regardless of the programming language you write your programs in (this is by the way something that is often overlooked when recruiting software developers where recruiters often look for experience with a particular programming language over a high level of understanding of the programming paradigm. The language used is often a minor detail, a good Java programmer will pick up C# in no time, and vice versa).
Other areas that haven’t aged much are data structures, algorithms, and relational databases. Sure, SQL server is always evolving and NOSQL databases has gained a lot of popularity recently, but the foundations laid out by Edgar F. Codd in the 1970’s are still highly relevant.
In conclusion, traditional technical books still has a place in the modern connected world. They are great for educational purposes when the goal is to learn about concepts and ideas that has proven to stay true over the years. It is also a nice feeling to grab a cup of coffee, pick up a real physical book, and flip between actual pages at a peaceful pace.