You've done a bit of research, and you've come across this thing. It's called a writer's group or a writer's circle. What it that, exactly, and what does it mean?
Well, each writing group or circle works by different rules, but the basic premise is the same:
A bunch of writers have gotten together and mutually decided to help each other up their writing game. They generally meet regularly, but sometimes not (let's be honest, trying to schedule a mutually agreeable time for everyone is nigh on impossible), and they share their work, asking for and expecting feedback. They do this in order to help them improve their craft, or, sometimes, help with a particularly nasty plot problem they're experiencing.
Writing groups are great places to meet with people who understand what you're going through, and to find a mutually supportive network to help you continue towards your writing goals. They are, on the whole, a fantastic resource for writers, and I can highly recommend them.
They can also, however, be horrendously destructive to a writer if they find themselves in the wrong group.
When searching for a writer's group, do your research. Look who is in that group. Do they have a reputation for being supportive and smart? Or are they known for being selfish and patronising? Do they write the stuff you're writing (in other words, would they understand what you're trying to achieve with your writing. There is nothing worse than a SFF writer caught up in a group whose main critique is that 'faeries don't exist.' Thank you, Sam. I KNOW)? Ask to sit in on a few meetings before deciding to join a group. If you dig the people and the vibe of the group, you've found a place to stay for a bit. If something seems a little off, don't join.
By this I do not mean only accept fawning praise from this group. That's not the point. But nor should you stay in a group that can do nothing but trash your work. You're there to level up, not get your soul destroyed.
In short, a writer's group is a small tribe of writers who have mutually agreed to gather and help one another improve their craft, solve sticky writing problems, and generally be a support network for one another. They useful, and great to be a part of... if you find the right fit for you.
Right, I have things to be getting on with this morning. Stick around and I'll talk about what to do once you've found your writing tribe.