Your coral is a Dipsastraea
Coral identification is a notoriously hard subject to get into, as corals are morphologically variable such that there is overlap in phenotype between multiple species/genera, and recent reclassifications have made correct identification even more confusing. Additionally, reinterpretation of species by later taxonomists such that the current species concept conflicts with the type specimen and original description and most readily accessible guides being unreliable to some degree have further obscured identification.
If you want to actually identify corals, I would recommend trying to find images of the type specimen(s) of the species you are trying to identify, as well as the original description of the species. This can be hard to do, as you will have to do some digging, and sometimes these will not be publicly accessible or have been uploaded to the internet.
As for guides, the most accessible guide is the Corals of the World website, though Veron is known for reinterpreting species concepts, and his IDs have varying degrees of reliability depending on the species. CotW's taxonomy is also outdated, with Veron opposing most of the recent molecular/genetic-based reclassifications. I personally would not recommend CotW, except for maybe the species Veron himself described. Joe Rowlett's Indo-Pacific Corals is a good guide for not just stony corals, but also soft corals, anemones, and more, although his book is a few years outdated. Russell Kelly's Coral Finder is also a good guide, but it does not cover species-level differences as much.
