ELK stack is a combination of 3 open-source products as below,
Elasticsearch, a search and analytics engine.
Logstash, that index the data to Elasticsearch. Logstash has a config file that has input,filter and output section. Config file looks like json file.
Kibana, a visualization tool which provides a web based GUI for a user. User can design the bar, plot reporting charts. In order to make Kibana and Elasticsearch interact, you need to make both server up and running. Then logstash will index the data to Elasticsearch. Then Kibana would read the data from Elasticsearch and visualize it.
DevOps is the practice of using set of tools, processes and practices to get good agility in software implementation to customers. It combines Dev (software development ) and Ops (information operations). DevOps shortens the development lifecycles and provides Continous Integration & Delivery. DevSecOps is when security features are included in DevOps CI/CD flow. NetOps is when network services are packaged to DevOps.
Jenkins jobs and Jenkins pipeline are essentially same, however pipeline is more staged flow of jobs. For Jenkins pipeline, Jenkinsfile is used. What is Jenkinsfile?Jenkinsfile is a text file placed in the root project directory. The Jenkinsfile has multiple stages like build, unit test, sonar test, functional, regression, integration, performance testing, deployment etc.