It is impossible to subsume all products that are available on the market into one law defining safety. The diversity is too big. One cannot compare a highly sophisticated drone with a wooden block box, e.g.
That is why there are standards for thousands of products. The products are grouped into multiple product groups. There is a good chance that multiple standards apply to one product.
Purchasing existing products
A seller must be sure that the products he or she sells are safe according to the legal standards of the European Union. This also applies to sourcing of existing products or importing them from China, for example. In that case, it is important to check whether the manufacturer or supplier has assessed product safety. If a supplier has done so and the products meet all safety requirements, the assessment report or a certificate is available.
Is no report or certificate available? Most likely, then safety has not been assessed. This means that it is now the responsibility of the seller to examine the products, or have them examined by another party.