DNS-records - records about the correspondence of the name and service information in the domain name system. Each entry has a specific purpose and use.
When specifying several records of the same type for one subdomain, if the records cannot be used simultaneously (we are talking about records A, AAAA, ALIAS, CNAME), then a random record will be given with each call. The system for determining the randomness of the transmitted record is RoundRobin. With such a system, you can create minimal and simple load balancers with random balancing results. It should be borne in mind that for all records, except MX, in this way it will not be possible to organize a scheme when, if the server is unavailable, the next record for the same domain / subdomain will be given by the first received record - this task can only be solved using a proxy server configured accordingly.