Yes, you need it for sure, it will store the logs and all the other info also in the SQL server, as uipath is a .Net application and sql server is also related to microsoft, they preferred SQL server I guess. You don’t need to bother, as you are using .Net framework already, most of the companies will also acquire SQL server license also.Check that
IIS is a server which is located in our machine. It will be there in every machine (based on the configs). It will run web applications when we deploy them in IIS similar to the one which we run while running the ANGULAR applications from Visual Studio Code or the MVC WEB API from Visual Studio. (we will get the URL as localhost). So, similarly, when we install Orchestrator, it will deploy a Web application as HTTPS (which is secured and requires a client certificate) that will run until you shut down the machine and restarts when you start
Thats based on your requirement. If you are the only one using this, you can use self signed certificate as well.