Intertek GS quality mark
The GS Mark is a voluntary safety mark which is highly regarded and valued by German consumers and manufacturers alike. Many consumers see the GS Mark as proof of quality. 

Intertek accredited by the German government
Any electrical, mechanical or electro-mechanical product bearing the GS Mark has been tested to, and complies with, the minimum requirements of the German Equipment and Product Safety Act (a.k.a. GPSG). The GS Mark (GS stands for Geprüfte Sicherheit – ‘Safety Tested’) is a licensed mark of the German government and may only be issued by an accredited product safety testing and certification agency. Intertek is one of the most well-known providers of GS certificates in Asian countries.
Source: http://www.intertek-twn.com

CE quality mark:

The CE marking found on may products implies the product is compliant with the specific rules applicable withe the European Economic Space (European Union, Switserland, Liechtenstein, Norway and Iceland) CE stand for "Conformité Européenne" which means "compliant with European rules".
The goal of hte CE mark is two fold. First goals is a free trade of goods between the countries in the EU. Second goals is to improve the safe use of producs. The CE mark is mandatory on a wide range of products including electrical devices. By putting the CE mark on the product the manufacturer declares his product is compliant with the European rules and all relevant procedures are followed..
Source: https://nl.wikipedia.org