Is it possible to write the hex file into the 8051 board with uVision without using Atmel Flip? What is the difference between using Flip and uVision?
"the hex file"
What hex file?
"the 8051 board"
What 8051 board?
"without using Atmel Flip?"
Only if you have a suitable alternative to Atmel Flip!
"What is the difference between using Flip and uVision?"
Flip is a utility for programming devices;
uVision is an IDE: basically, it is just a "front-end" or "interface" to other tools that do the actual work - ie, the Compiler, Assembler, Linker etc.
See this diagram: http://www.keil.com/c51/devproc.asp
uVision also provides the facility to control 3rd-party utilities such as Atmel Flip:
http://www.keil.com/support/man/docs/uv4/uv4_dg_flashutil.htm
http://www.keil.com/support/man/docs/uv4/uv4_dg_tools_menu.htm