Merging is available in CRM on accounts, contacts and leads. It allows users (with the right permissions) to select two records and merge the information contained in both records into one winning record. The losing record will be deactivated. When two records are merged, all the child records associated to the losing record will be connected to the winning record, and this includes activities.
Click on The CRM menu
Click ACTIVE ACCOUNTS view
Select the Records that will be merged together
Then you will get a side-by-side comparison between the two records
You can select what information you would prefer to be in the record. The information picked will remain active, whereas the other record will remain inactive.
So one thing you will notice is that you’re going to notice it says the selected records are merged and the subordinate or losing record has been deactivated.