ATA Drive vs Flash Storage I am a student who is looking to buy a Macbook. My budget is 1200 USD. 

I will be using it for programming mostly. 

I came across 2 laptops:

13-inch MacBook Pro Item Price:$1,134.00
  Hardware
2.5GHz Dual-core Intel Core i5, Turbo Boost up to 3.1GHz
8GB 1600MHz DDR3 SDRAM — 2x4GB
1TB Serial ATA Drive @ 5400 rpm
SuperDrive 8x (DVD±R DL/DVD±RW/CD-RW)


Air:

13-inch MacBook Air Item Price:$1,149.00    
Hardware
1.6GHz Dual-Core Intel Core i5, Turbo Boost up to 2.7GHz
Intel HD Graphics 6000
8GB 1600MHz LPDDR3 SDRAM
256GB PCIe-based Flash Storage


Macbook Pro seems like it has more processing speed &amp; more storage. However, Air Model has a Flash storage.

How much difference does the Flash Storage make? Is it worth sacrificing on clock speed for flash storage?
It depends on what kind of programming you're going to do. Especially if you going to test the programs that you're developing.

Any of these "is it worth it" questions are going to be highly subjective.

I would think that an average programmer would value the SSD more than the extra CPU speed, as compiling/building involves a lot of small files which the SSD will handle faster than the ordinary hard drive. However, a RAM drive would be faster than either disk. So it depends on your setup.

Also remember that the MacBook Pro is a 2012 model compared to the 2015 MacBook Air, so you cannot compare the CPU as simply 2.5 Ghz vs. 1.6 Ghz. This could lead you to believe that the MacBook Pro has a CPU that is 56% faster than the MacBook Air - however benchmarks show that the CPU is really only about 4% faster. The GPU is also faster on the Air (Intel HD6000 vs. Intel HD4000).