@Santana ********
It's an Electronic Travel Authorisation
If you have traveled to the Philippines you will understand what it is..
It's a website or App where you must register your intention to enter the country before you travel..
It's only a proposal at the moment and the Thai government released some information about it in the media with a very optimistic date for implementation but that's already been postponed..
Just ignore it and there will be plenty of information about it once it's actually rolled out including a trial period where it won't be compulsory.