Basically, it's about saving a large portion of your income (often >40%) to invest, so you have the option to stop working well before typical retirement age. Many people pursuing FIRE shoot for retirement starting sometime between 35-50, but anything before typical retirement age counts.

But even if you're not specifically pursuing early retirement, you can still join in discussion here, since many here would be pretty knowledgeable about investing, tax planning, etc.

We don't have a lot of posts here because the basics of FIRE are pretty simple. But if you're interested in some reading, check out the sidebar, and here are a few articles to get started with:

Shockingly Simple Math Behind Early Retirement - see what savings rate (percent of income you save) you'd need to retire in a given amount of time
HSA as the ultimate retirement account - great intro into a different way of thinking about money
Never Pay Taxes Again - goes over tax brackets and a high level intro into optimizing retirement withdrawals to avoid taxes

The second two are US-centric, but the first is generally applicable to other countries. If you're outside the US, I recommend still reading the last one since a lot of countries have similar tax laws and the concepts can be applied elsewhere. I linked three different blogs so you can explore the older posts (lots of good content on all three; the first is linked in the sidebar), and I'm happy to link a few more if you can let me know what your interests are.

I'm trying to post a bit more often, so I'm happy to make a top-level post if there's something you think would make for good discussion.