What is a Charter school? It's free? How is it different from Public school?.
I'm not an expert on what they are. My DD attends a local Charter and we are thrilled, I mean totally thrilled. Our school is ranked "High Achieving" there are only 2 elems, and no middle or high schools in our district with that kind of ranking. Our school is heavy on math and sciences, its awesome. The school is fully accredited and well known here in N. Nevada. It started out 10 years ago as a middle school 7th/8th grade and has now expanded and covers K-12 with 2 campus's, one for the elem and the other the mid/high school. They are currently looking for a 3rd campus to move the high school to.
We have a lot of competitive clubs:
Lego Robotics, Future/Sim City, Science Olympiads etc.
We don't have organized sports, we are not big enough.
We are headed to Las Vegas (8 hours away) for the Future City regional competition next month.
Our goal: Beat the Homeschoolers!

they are our biggest competition.
Kids must try out to be in most of these clubs, not all kids make it and that is just the way it is.
Here is what I do know:
We are a public school and do receive funding from the state.
The school is autonomous and can spend the funding anyway they choose.
They are still accountable via standardized tests etc.
Our teachers receive the same benefits of the other teachers in our district but openings at our school are rare and highly sought after. Our percentage of "qualified in their subject" teachers far surpasses our district average.
Enrollment is open to all kids but there is a process and then there are academic requirements that must be met in order to stay enrolled.
Behavior problems are not tolerated.
We must provide all transportation to/from school as well as field trips
Class sizes thru 5th grade were capped at 18
I pay $150 per semester for DD to attend.
I also must purchase uniforms.
All books and most supplies are provided
our technology is state of the art
Security is top notch, the entire school has surveilance
We have to maintain our school, the District has nothing to do with the property or what we do. We recently put in shade structures. The parents dug the holes, the parents did all the work etc. there was no having to go through the district etc. which is soooo dang costly. Parents paint, parents plumb etc. everything has permits etc. its not like it is done half way but its done by us not the corporate giant of waste that is our local school district.
My DD is challenged at every turn, she is expected to excel, the kids are taught that competition is good and there is lots of academic competition and an extensive reward system.
The staff is dedicated and love what they do. Even in 5th grade my DD had 2 teachers. The school assessed the talents of the kids in 4th and 5th grade and then paired them up with the teachers with the best suited strengths.
Example, DD's Home room teacher was really strong in Science and Math so she had all the top science/math kids and that is all she taught. She had the 5th grade in the morning and the 4th grade in the afternoon. Meanwhile one of the 4th grade teachers was really strong in reading/language so she taught those subjects exclusively to the 2 grades. The result was that DD got the best the school had for each subject she was taught.
This has continued into the middle school where DD is now.
I agree with all others that every single household has different needs.
Both my kids went to private all day K
DS then went public all the way through high school and is now a Jr. in college. I will say he was not as prepared for college as we would have liked and I know a lot of that had to do with the overall fair quality of his public school education. However, the majority of the private schools here are religious based and not any better and often are worse than our public schools.
Private does not automatically mean good. Know what you are signing up for.
DD went public through 3rd grade, same school her brother went to but what a difference 10 years made. By the time she got to the 3rd grade the school was failing miserably, all the staff that was around when DS went were gone. In a nutshell the school sucked so we started looking for alternatives. We found our charter and put DD into the enrollment lottery for 4th grade. She got a spot and this is where she will stay until at least 8th grade.
I would like her to stay through high school but she is not into athletics so that opens the door for us to variance her to high schools other than what we are zoned for.
Only time will tell. She loves the middle school and I am thinking this might be where she stays until she finishes high school. This school averages 16 graduating Sr's a year and they all went on to 4 year colleges. It has impressive statistics.
Warning, not all charters are created equal, some even here in my area have become the place for the problem children, and even worse the problem children with the problem (oh not my child!) parents. Like private, do your research and know what you are getting into.
Good luck, its a never ending decision process this whole being a parent thing!