What are the IPS and TN displays?

In Plane Switching(IPS) and Twisted Nematic(TN) is a kind of TFT LCDs(Thin Flim Transistor Liquid Crystal Displays). LCDs rely on the light modulating properties of energized liquid crystals and along with coordinated light filtering polarizers that are both behind and infront of the crystals to control what appears on the screen. By appling voltage to each crystal(or not), light is made to pass through the polarizers (or not). When these changed are made in microsecond intervals, you get smooth moving images.

TN and IPS displays differ in how their light-influening polaizer layers are aligned. When polarizers are aligned similarly, light can pass through, but when they are put in different orientations, light is blocked. And when you place liquid crystal molecules between the polarizer layers and apply voltage, The picture is produced.

IPS Display

IPS displays are popular for its eye catching color and wide viewing angles.IPS polarizers are aligned in parallel, which would normally allow all light to pass through. But again, the resting crystal molecules twist the light to disprut the normal flow. So IPS displays work in opposite to the TN displays. Rather than the application of voltage blocking light, the voltage lets light get through. it prevents the liquid crystals from twisting the light so it can pass through the parallel polarizers as usual.

Advantages of IPS Display

Wider viewing angles: The parallel orientation of the IPS display’s crystals and polarizers make them far easier to see extreme angles.
Greater variety of colors: Most IPS displays feature 8-bit panels(8 bits red, 8 bits green , 8 bits blue), so they can better reproduce the full 24-bit color palette of a typical grapics processor(8 * 3 = 24). Many TN displays have 6- bit panels (6 * 3= 18) and use extra steps to emulate the full color range.
Improved color accuracy: IPS displays are generally built to meet a higher price point than TN ones and use better backlights capable of generating far wider color gamuts (for example, Adobe RGB versus the older sRGB). The additional hues and shades allow more realistic, true- to-life colors.

Disadvantage of IPS over TN Display

The disadvantage of IPS monitors compared to TN ones is their relatively slower refresh rates and slower response times.

These delays are measured in milliseconds so majority of users will not be impacted. IPS is fast enough for streming movies, making video calls and so on.

TN Display

TN polarizers are aligned perpendicular to each other. Without voltage, the liquid crystal molecules naturally “twist” the light so it can go from a vertically-aligned polarizer, be twisted in the crystals, and then pass through the associated horizontal polarizer. But if you apply voltage, the light no longer gets twisted and the perpendicular polarizer orientations block light from passing through.

Advantage of TN Display

Faster response times and refresh rates: TN display is faster at refresing the onscreen imagery and activating/deactivating each pixel. And while the difference is only few milliseconds. The best TN panels boast response times as fast as 1 ms to 3 ms faster than top-end IPS models. Generally PC gamers typically want the fastest refresh rates and response times.
Lower Prices: TN display will cost less than an IPS one with equivalent resolution.

Conclusion

If you want fast response time and high refresh rate with lower price go for TN display. On other hand, if you want better viewing angle and better color reproduction with little higher price go for IPS Display.