28. What is a Solution and how do you move components across environments?

A Solution is a container used to group related components like apps, flows, tables, and dashboards.
For example, if you build a leave management system, you can place all related items inside one Solution.
To move it to another environment, you export the solution (as Managed or Unmanaged) and then import it into the target environment (like Test or Production).
Solutions make deployment structured and professional.