You said there's a good difference between all the classes, how much of a difference?
So everyone does dps. Any buffs or debuffs are sort of incidental parts of your dps rotation (though using them optimally and timing them with the rest of the raid is an important part of optimizing dps windows). The exception is healers, though they still spend a lot of their time doing damage (heals are big and impactful at higher levels, so you try to minimize time spent healing and maximize time spent dpsing).
Many classes have some sort of main single target combo sequence where you do A then B then C, some aoe skills, a stun and/or interrupt, etc and thus share a similar structure. However, there are many jobs and so quite a few that pull away from this norm.
As a rule, physical ranged characters can cast all their skills while moving and thus have incredible mobility during combat, making them responsible for many raid mechanics. Melee characters by virtue of being melee are less mobile but tend to have better damage
if you can maintain uptime on a boss, and they have a number of mobility skills to help facilitate that. Casters are sort of a mix.
Unfortunately how classes play at lv10 or lv30 or even lv50 is quite different from how they play at lv80