Kanban (agile) boards are visual representations of a workflow (roughly translated to columns) and the tasks (cards) that follow that workflow.

Boards bin statuses into columns but aren't always 1-1 eg. "Open","Reopened", and "On Hold" could all be binned under a board's "To Do" column.

Kanban boards are populated by saved searches (using JQL, examples follow below) that tell the board what cards to display. Quick filters are optionally used to further refine the cards displayed. Swimlanes are a third implementation of this search language that bin cards into rows.

JIRA query language (JQL) is a syntax used to help search for JIRA issues. Atlassian has an excellent full length tutorial on JQL here, but some examples are as follows:

"Return all issues that were made in the LCSET project in the last five days"

• project = LCSET and created >= -5d

   

"Return all issues in the SRS project that are currently in progress"

• project = SRS and status = "In Progress" 
  
  

A more complicated example - the JQL behind the SRS board (as of 2/2018) is the following, and is saved in a filter called "SRS Production". 

• level is EMPTY AND project in (LCSET, GAPREQ, PICO, XTR) AND type != Sub-task AND status in (open) OR project = "Sample Retrieval and Storage" AND (status not in (closed, done) OR resolved > -3d) ORDER BY Rank ASC