The T-code SM50 gives process overview.
Steps to know which is our work process by PID
1) Double click on the process-->go to Backg Tab-->click on Batch monitor-->double click on the job name-->click on Job details In which the last column would show the WP number/PID-->Copy the PID and search for your job in sm50, It gives pid no, and other details.
2) Using that pid no Go to process option and select cancel with core(IF you want to kill the JOB)
DIA - Work process for executing dialog steps in user transactions
UPD - Update process for executing update requests
ENQ - Process for executing enqueue requests
BTC - Process for executing batch requests
SPO - Process for executing spool requests
UP2 - Process for executing V2 update requests
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