PostgreSQL is a free, open-source relational database management system, known as the most successful database in the world. It has a long history dating back to 1985, started as a research project at the University of California, Berkeley. It not only supports many advanced features, but its performance can even exceed that of most databases in many application scenarios, including commercial databases. In fact, PostgreSQL has been considered one of the most popular databases in the world, one of the most admired databases by developers, and one of the databases with the strongest user demand.

PMBOK (Project Management Body of Knowledge) Guide is the classic work of PMI (Project Management Institute) in United States. It has become one of the national standard for project management in the United States, and the de facto world standard for knowledge and practice in project management today. If you want to easily pass the PMP exam, Head First PMP can be your first choice.

Unity makes it easy for developers to build games without getting bogged down in unimportant details. It handles a lot of the details for the user, allowing them to focus on gameplay, graphics, and user experience development. Its pre-built resources are of reliable quality, and they are a complete, huge ecosystem. In addition, Unity has an active and powerful development community where you can get a lot of help.

In 2007, Google decided to create a new programming language to replace C++, the Go language. Although it does not replace C++ as desired, it has the similar performance of C and the similar development efficiency of parsing languages and near-perfect compilation speed. Many programmers regard it as "the C language of the 21st century", which is more and more widely used in cloud computing, edge computing, big data, micro services, Internet of things, and high concurrency domain.

If you find yourself having trouble learning Algebra and feeling confused about algebraic concepts, equations and logic, then Head First Algebra in the Head First series is the best learner's guide for you. Like all books in this series, it uses a visually rich format designed for the way the brain works. Based on the latest research in neurobiology, cognitive science and learning theory, this book combines words and pictures in a playful, mixed-media style that not only helps readers understand a subject, but also to remember it.