Australia

Big Room is slower than 90s Trance, usually more around the 126 - 130 BPM mark (old school Trance is more in the mid-to-high 130s, sometimes up to 142 BPM). In Big Room there are usually other elements tied directly to the kick as well, like snares, claps, hats or the bass which gives it a "jumpy" kind of feel. If you were to compare it to an older genre, it's a lot closer to something like Hands Up or Jumpstyle which are also a big jumping genres (also think classic Eurodance like Basshunter). Designed for festivals and raves or anywhere you have tons of people packed in a tight area where they can only move vertically.

Aside from generally being faster, Trance also has a lot more complexity which means there is a lot more variety in how you can dance to it. There are extended breakdowns and slower build-ups, which is where the name comes from (people feel like they're in a trance). Swaying, hand movements like gloving, and Tecktonik are some of the other common ways people dance to Trance subgenres. Trance and its subgenres are much more underground and niche than House and its subgenres though, which I suspect is due to the complexity and tempo making it more challenging and individualistic to dance to (some people feel more self-conscious to dance in their own unique way). Stuff like Big Room is super accessible because the structure is short and basic and it's built around very friendly "drops" after which everyone can just jump up and down together, which I think is another reason why it has that Saturday night mainstream club popularity.

There is of course overlap between House and Trance since they are both four-on-the-floor genres and they both have tons of subgenres, some of which blend elements of both. For example, Progressive Trance is a similar tempo to House but retains the complexity and melodic structuring of Trance. In the 2010s there was also this subgenre called "Progressive House", which had nothing to do with the more traditional Progressive House and was more like a predecessor to Big Room. "Progressive House" had some more Trance elements like atmospheric (but shorter) breakdowns and big uplifting synth leads, but it was still very much a House subgenre.

Anyway, subgenres of electronic dance music can get quite messy and there is often a lot of blending and overlap which means it's often up to the individual how they want to define a particular track. In the case of Big Room and 90s Trance, however, there are so many major differences that they live quite firmly in their own distinct categories.