SQL Server jobs

Hi ,

There are multiple jobs on my SQL Server and I want to list the jobs. 

1: When i execute 'exec msdb..sp_help_job ' I get 64 jobs listed

2: When i execute below query, I get 66 jobs listed

Select j1.ins_id max_ins_id,job.job_id,min_ins_id,j1.run_duration                       
,j1.run_status, job.category_id,j2.sql_message_id,ja.strt_exec_date From                
msdb..sysjobs job with (NOLOCK) Left JOIN (Select                                       
ins_id,a.job_id,min_ins_id,a.run_duration,a.run_status From                             
msdb.dbo.sysjobhistory a with (NOLOCK) INNER JOIN  (Select                              
max(a.instance_id)ins_id,min(a.instance_id) min_ins_id,a.job_id From                    
msdb.dbo.sysjobhistory a with (NOLOCK),msdb.dbo.sysjobhistory b with                    
(NOLOCK) where a.job_id = b.job_id  Group by a.job_id)a1 on a1.ins_id=                  
a.instance_id)j1  ON job.job_id=j1.job_id Left JOIN                                     
msdb.dbo.sysjobhistory j2 on min_ins_id=j2.instance_id Left JOIN (select                
job_id,max(start_execution_date) as strt_exec_date from                                 
msdb..sysjobactivity with (NOLOCK) group by job_id) as ja on                            
job.job_id=ja.job_id 

I would like to know the reason for this that why such inconsistency is seen and the reason for filtering.

Which attribute or table is casuing this?

Thanks.