What is Jenkins:
Jenkins is an open-source continuous integration and continuous delivery tool written in Java. It's an automation server used to build and deliver software projects. Jenkins was forked from another project called Hudson after a dispute with Oracle.
CI/CD:
Continuous integration, is the practice in software engineering of merging all developer working copies to a shared mainline several times a day
Continuous Integration is a software development practice that integrates code into a shared repository frequently. This is done by developers several times a day each time they update the codebase. Each of these integrations can then be tested automatically.
Continuous delivery, on the other side, abbreviated as CD, is a software engineering approach in which teams produce software in short cycles, ensuring that the software can be reliably released at any time.
Continuous Delivery (CI) is a DevOps practice that refers to the building, testing, and delivering improvements to the software code. The most important part of the CD is that the code is always in a deployable state.
Docker
Docker is the most popular container software. To start using docker, You need the Docker Engine, it's the Docker runtime.
Docker Enginee the docker runtime software to make run docker images
Docker hub Online service to store and fetch docker images and also allow you to build docker images online
Docker provides you with isolation. You ship a binary the docker image, with all the dependencies. No more "It works on my machine, but not in production."
Everyone will have the same container image of Jenkins. So everyone who runs docker one and then