What is necessary to understand about the wine label, how to choose a wine by label

https://www.google.com.br/search?hl=pt-BR&tbm=isch&source=hp&biw=1242&bih=602&ei=O6P5Wo7IJsqmwgSxz6vQAg&q=r%C3%B3tulo+de+vinho&oq=r%C3%B3tulo+de+vinho&gs_l=img.3..0l3j0i30k1l2j0i8i30k1.1047.4832.0.5338.15.14.0.1.1.0.296.2492.0j2j9.11.0….0…1ac.1.64.img..3.12.2495….0.4XcrhSMR7w0#imgrc=TqZonfJBljxDRM: Although it is simple, this is a very common doubt and that causes some confusionwhen selecting a wine...