Understand BLE handles

[Paul]

I am using sniffer to monitor the BLE packets. I noticed that when master is reading the list of the characteristics, sometime there are 2 handles involved, sometime there 3 handles involve.

I am attaching two screenshots here to see if anyone can explain.

Thanks

[FormerMember]

The read request "Read by type request, GATT Characteristic Declaration" will search for characteristic declarations in the handle range 0x18 to 0x2b. Only the characteristic declarations will be returned. It means that if starting to search from handle 0x18 and the first handle that is returned is 0x19, handle 0x18 is not a characteristic. Maybe handle 0x18 is a service declaration?