please suggest me good professional FDM 3d printer for learning 3d printing technology.
Accepted answer
Without mentioning your budget, it's impossible to help...
According to www.all3dp.com :
Best 3D Printer Under $200: Creality Ender 3
Best 3D Printer Under $300: Creality Ender 3 Pro
Best 3D Printer Under $500: Creality CR-10S
Best 3D Printer Under $1000: Original Prusa i3 MK3S
Best 3D Printer for Beginners: Tiertime UP mini 2 ES
Best Dual Extruder 3D Printer: Ultimaker S5