In the Spring Batch step-scope documentation, there are three unexplained spring-batch context maps: jobParameters, jobExecutionContext, and
#{jobParameters}, #{jobExecutionContext} and #{stepExecutionContext} are the spEL (Spring Expression Language) counterpart of JobParameters, JobExecution and StepExecution objects available in late-binding to allow non-static access to this objects values from step scoped object.
They support access as Maps so you can access the ExecutionContext associated to JobExecution and StepExecution and values stored in JobParameters.
Also check StepScope documentation for more information.