In that specific case, I can tell you that I normally create a channel for that kind of content - so a channel like “Home Welcome”. I prefer to do it that way since it allows the client to either edit the existing entry, or just post a new one, keeping the older one in the system for resurrection later if desired (giving them the ability to A/B text their welcome message content internally, for example). How you choose to pull the entries from that channel into the home page partly depends on a few key things. In my case, I normally treat the “home welcome” channel as the chief content of the home page - as such, a meta description, alternate title, and meta keywords are part of that channel, and I put that content dynamically into the page header. As a result, the channel entries tag pair for that channel tends to be the main one in my home page template, and any other content appearing from other channels on the home page tends to be drawn in using snippets.
There are many ways to do the same thing in EE, so this is just one example of how I commonly approach what you asked about. Hope it helps.