A couple of basic website tech questions

I'd appreciate if someone with website experience could answer these questions please.

1. Modern business webpages have a "modern" look where the page extends along the full width of the screen, and has separate sections where images, videos and text blocks (e.g. testimonials) can be easily set up on the page. Is there a specific name for this style of website? e.g. SmartPassiveIncome.com

2. I understand wordpress plugins and themes can do a lot of this sort of presentation work along with a lot of other useful tasks marketers use (optimizepress is a great example). If not using wordpress and using a more generic system for creating websites, what are the most common modern coding languages and systems (frameworks?) that are popular to use?

3. There are a lot of websites now that offer all kinds of powerful apps and services, e.g. graphics manipulation, reporting "hidden" social media statistics, keyword research, etc. Again, what coding languages and systems are commonly used to program and deliver these sort of powerful online apps?

I am interested in the frameworks that are powerful, versatile and popular amongst the modern entrepreneurs. Your replies to each question is very much appreciated.

Cheers, Mat