Do I need to include only the woff font?

Question

css

Hello.
There are two questions about fonts.
1) Why do we not specify 'format' in the screenshot below under the blue line, but do it in other containers?
2) In this video, Vadim Makeev says that containers like eot, ttf, svg, eot are not needed, now only woff and woff2 are needed.
Hence the question, firstly, what do you think about this statement, and secondly, if there is no woff2 container, is it possible to get by with woff alone?
Timecode 1:27
https://youtu.be/MTQ9FpT3ayc

Answer 1

1. Because this is the syntax for IE either 6 or 7 versions. You haven't even seen him, I guess.
2. Absolutely agree with Vadim.
Yes, if there is no woff2, then woff is enough. All browsers that understand woff2 also understand woff, it's just that woff2 is easier.
Browsers that don’t even understand woff are ancient mastodons (it’s quite possible that on ancient computers) and it’s inhumane to load them with extra fonts