The 'stages' section in a Jenkinsfile is used to define the stages of a pipeline. Each stage represents a phase in your build process, and within each stage, you can define multiple steps.

Jenkins can automatically poll source control systems like Git to detect changes in the source code. This enables Jenkins to trigger builds when changes are pushed to the repository.

The best practice involves using Shared Libraries to modularize and reuse parts of job definitions. Shared Libraries allow you to define common functionality and use it across multiple projects.

Jenkins can be integrated with LDAP (Lightweight Directory Access Protocol) for role-based access control. LDAP integration enables the use of existing user accounts and groups for managing access to Jenkins resources.

The Plugin Manager page in Jenkins is where users can view and manage all installed plugins, including their versions and statuses. It's a crucial part of maintaining and updating Jenkins functionality.

Offloading jobs to distributed nodes is achieved by configuring Jenkins Slaves. These are additional machines that Jenkins can use to execute build jobs, thereby improving performance.

Jenkins administrators can ensure backward compatibility by testing plugin updates in a staging environment before applying them to the production environment. This helps identify and address any compatibility issues proactively.

Jenkins's integration with Kubernetes is key for automating deployments in a continuous delivery pipeline. Kubernetes provides container orchestration, allowing for efficient deployment, scaling, and management of containerized applications.

The use of a Dependency Manager can resolve conflicts in a Jenkins pipeline caused by dependency issues. It helps manage and resolve dependencies efficiently, ensuring a smoother pipeline execution.

A Jenkinsfile is primarily used for defining the pipeline as code. It allows you to describe the entire build process, including stages, steps, and conditions, in a script format that can be versioned along with your code.

In a parameterized build, the "Array" parameter type is used for accepting multiple string inputs. This allows users to input a list of values during the build process.

The Node Management plugin is vital for managing and scaling Jenkins nodes in a distributed setup. It allows administrators to add, remove, and monitor nodes, ensuring efficient resource utilization.