Final answer:
Elastic (ELK Stack) is primarily utilized on the HTTP network protocol for interactions with external clients and services, although its components also use TCP internally and can handle other protocols such as UDP.
Step-by-step explanation:
Elastic, also known as the Elastic Stack or ELK Stack (an acronym for Elasticsearch, Logstash, and Kibana), is commonly utilized on the HTTP network protocol. While Elastic Stack components can communicate internally over TCP, when considering its interaction with external clients and services, such as when a browser accesses Kibana or a user sends a query to Elasticsearch, the HTTP protocol is used. Additionally, Logstash can accept data over TCP as well as HTTP, and it can send and receive data over a multitude of other protocols, like UDP, but when interacting with Elasticsearch for indexing, HTTP is generally employed.