Hi there! I have a question that I am often asked what does the blue certified validator logo mean, what is its purpose, what criteria are used to obtain it, and what is the difference with a validator who does not have it, is there a risk?

That's just like Twitter's verified symbol. A verified SP (Staking Provider) is most likely an Elrond partner with technical experience to run nodes in terms of quality, experience, safety and so on. Also, some of the verified SPs are building different solutions and projects to grow the Elrond ecosystem and the adoption. But this doesn't mean you cannot support and trust non-verified SPs as well, but please do some due diligence before staking and try to research about the team, community and their technical experience to run nodes. Being a non-custodial staking, anybody can be a validator/staking provider that's why research is important, in the end...it's your EGLD.