Root is needed if you want to Flash Custom ROMs and kernels.You can root Samsung galaxy j2, tweak your phone,overclock the CPU and use rooted application after rooting your device.

Don’t miss : LineageOs 14.1 Android Nougat Rom for Galaxy J2 is now available!

Remember rooting android device may void your warranty.(Credit-Chainfire)

Requirements 

 
Make Sure TWRP is installed On Your
device.

How to Root Samsung Galaxy J2 SM-
J200H with SuperSU 

 
Step By Step Guide
  1. Download SuperSu Zip
  2. Place the SuperSu zip file to the internal memory of your Galaxy J2
  3. Now Boot your device into recovery mode(press and hold Volume Down button +press Power button).
  4. Choose install, and then select the SuperSU Zip file
  5. Tap on Reboot system
Done!!! Your Samsung Galaxy J2 LTE is now rooted. In case you get stuck at boot loop, go to recovery and wipe cache and data