CE Marking on a product is a manufacturer's declaration that the product complies with the essential requirements of the relevant European health, safety and environmental protection legislation, in practice by many of the so-called Product Directives.*
*Product Directives contains the "essential requirements" and/or "performance levels" and "Harmonized Standards" to which the products must conform. Harmonized Standards are the technical specifications (European Standards or Harmonization Documents) which are established by several European standards agencies (CEN, CENELEC, etc).

CEN stands for European Committee for Standardization.
CENELEC stands for European Committee for Electrotechnical Standardization.
CE Marking on a product indicates to governmental officials that the product may be legally placed on the market in their country.
CE Marking on a product ensures the free movement of the product within the EFTA & European Union (EU) single market (total 28 countries), and
CE Marking on a product permits the withdrawal of the non-conforming products by customs and enforcement/vigilance authorities