I am a beginner in photography. I want to buy a dSLR. After a lot of googling, I found that the newly launched Canon 200D/SL2 is better than the 700D/T5i. Is this really so? I am confused, because if it's better than the 700D, why is its price nearly that of the 700D's?
You're not taking into account the age of the two models you're looking at. See this chart on Wikipedia, which lays out the Canon dSLR models by age and tier.
The 700D is a 2013 camera; its current "successor" model is the 800D. The 200D was just released this year. If you want to compare same-era models, it would be the 100D vs. the 700D, and the 200D vs. the 800D. And as you would expect, the higher-tiered model will have better specs and a higher pricetag. But when you compare a lower-tiered newer model with a higher-tiered older model, the specs may be higher and the pricetags roughly the same.
Cameras, as they age get cheaper. Newer/lower end cameras often inherit technology from older or higher-end cameras.
What you are probably also not seeing in the specs, however, are the handling characteristics, which are the main differentiations between the two tiers. Things like AF system control/performance or number and layout of physical buttons. The "T" dRebel line sits above that of the smaller SLs because some features/buttons were eliminated to make a smaller camera body.
If you're looking for a pure number compared to number style answer you should look here; https://www.dpreview.com/products/compare/side-by-side?products=canon_eos700d&products=canon_eos200d&sortDir=ascending
However, there is more important things such as what is your budget? Don't spend your entire budget on the body or body and kit lens, the most important part is the glass (lens) so make sure you've left some on the side to invest into good glass, it'll help a lot with your photography.