To increase the efficiency of production, knowledge and its application in various engineering disciplines is required. This also includes the fluid technology which is subdivided in hydraulics and pneumatics. With this book the author especially intends to introduce the reader in the physical principles of hydraulics. Recource is made on the book "Grundlagen der Hydraulik" published in the German language. It appears in the CARL HANSER-Verlag and is now in the 7th-edition. The book presented here, offers the possibility familiarizing themselves without spending too much time with the physical principles of hydraulics. This particularly applies for students at universities and technical schools. In addition the book will also be of help for those readers which are as technicans in professional practice and want to refresh their basic physical skills in the field of hydraulics. In the last chapter the reader will find 10 examples with the detailed presentation of the solution path by the "step by step"-method (each step is commented); clarity of the path to find the solution is thus given.