Hello!
These are not the same things. if you could clarify what you're trying to do then we would be able to answer your question a lot better!
The hotspot functionality is for service providers to streamline the process of bringing client devices onto the network. Check out this link to understand Passpoint
The Splash page functionality is for controlling the authentication method to your WiFi. A splash page is what the user sees when they try to enter your network (You typically see this in hotels and airports)
Hope this helps! Feel free to elaborate on what you're trying to achieve and we might be able to help you more 🙂