How authorization works in EOS dapps? I mean in application layer. For example in a trello like application how we manage to just the participants in the project are able to see the tasks?
Accounts in Eos are collection of authorizations,these flexible authorization structure can be managed by single or multiple users based on permissions configured.
shortly Named Permision Levels groups give access to particular action to execute. for eg, in steemit
posting permision key let who ever has it will post on be half of you.
you can hardcode these named permisions to your needs and give acess to particular group of people or bots to work for you