Depends on the instance and the community. I’m sure lemmy.world admins have a quite different workflow than smaller instances.

For programming.dev, most of our work in regards to the community is removing spam/scams/CSAM and the occasional instance rule breaking post. A lot of our communities are also admin moderated due to lack of moderators. In those instance we have a placeholder moderater account and use our admin accounts to moderate.

Speaking purely from a general lemmy standpoint, admins can do everything a moderator can do across every community. We can also view who votes and downvotes.

Unique for admins is that we can ban users from the entire site, not just a community, purge a user from the database (includes every post and comment they’ve made) and purge posts. We can also choose to speak as a “moderater” which is similar to normal moderaters, only with an admin symbol instead.

If the instance also require applications to be approved, we can see every application and approve/deny them.

We also see every report that involves our instance, be it a report on local community, or a local user reporting something on a federated community.

Admins can do pretty much anything they want, but the rules of the fediverse will dictate if and how it propagates to other instances.

So as an admin I can ban you from my instance and moderate your community however I want, but since my instance isn’t authorized to do those actions on your behalf or the community’s behalf, I would only see it from my instance perspective. Any lemmy.world admin can ban you globally, or moderate your community globally, since they host both your user account and community. If you’re a mod of a community on lemmy.ml, lemmy.world can ban your user account, but can only moderate their view of the lemmy.ml community as seen from lemmy.world, and lemmy.ml admins can moderate the community but not your account.

From Boost’s perspective, you don’t care, an admin is effectively a moderator of everything and some more. I’m not sure the purge option is available to regular moderators, but admins have the option to completely nuke posts (usually used for CSAM and other stuff you really don’t want to exist on your server).

If you’d like an admin account to play around, feel free to register on my instance and I’ll give you temporary admin.

It’s also really easy to run locally with Docker as well, if you want to implement and test more admin stuff. But it’s mostly mod tools that matters, the rest is fairly mundane: manage site logo and name, sidebar, configuration options, federation settings, user signups approvals.