Apex Trigger | Apex Batch |
Triggers run each time a DML operation is called against a record | Batch Apex runs across a (possibly large) set of data and performs some type of processing on it |
A trigger is Apexcode that executes before or after some event (i.e. insert,update,delete,merge,upsert,undelete) | Batch Apex runs whenever it is specifically called (or scheduled to run). |
trigger not queued for run, which cause immediat action. | Batch queued to run, which may cause delays in starting.There's a limit of 5 batches in play at any time. but when that queue is full (Max. limit 5 concurrent batches), the job fails instead of being rescheduled for later processing. |