An academy can be stand alone or part of a multi academy trust (MAT). The MAT is a chain of schools under the same organisation- could be two, three, five or a much bigger number. A stand alone will be a school that becomes an academy on it's own. That's probably going to be less likely in this brave new world.
Academy trusts can share resources, including staff if necessary. They can set their own curriculum and are free from the control of the local authority. Initially there will be additional monetary resource, but I don't know how long that lasts. Trusts will often have a highly paid chief executive and will operate very much on a business model.
They are not obliged to hire staff with QTS- qualified teacher status, so it is possible that unqualified staff will be employed, although hat doesn't necessarily mean they will have no qualifications, just no teaching qualification.
I would be concerned about issues like application criteria. Theoretically, it must be possible for a child to be unable to obtain a place at any school, if all of those applied to insist they have no space or simply refuse to accept a child. The local authority is currently obliged to offer a place, although it may not be one a parent chooses. The local authority will have no place in the education system and will be unable to exert any influence on schools.
As a parent, aside from the application process, you may not notice any great chsnges immediately. Then again you might. It was always mooted that academies would raise standards, but there are failing academies, academies that are in financial difficulty and chief executives who are more interested in the business model and less in the education and progress of children.
I'm glad I left the profession when I did- before it became a data driven business.