Overview of the present-day concentrated solar energy (CSE) technologies is presented. Approaches to concentrating solar energy are reviewed and the current projects worldwide of CSE technologies are compared. This paper presents general descriptions, current projects and summary of the CSE technologies. Parabolic trough collectors (PTCs) technology is found to be a mature technology. The linear Fresnel collectors (LFCs) technology is still in the experimental stage. The tower solar power (TSP) technology is preferred for large scale due to the cheapness. Sterling/dish collectors (SDCs) technology is designed especially for remote applications and has the highest overall efficiency and the highest operating temperature. The application areas show that CSE can be used in a wide variety of systems, could provide significant environmental and monetary benefits.