"Feedin" app, what does it show exactly?

Hello.

I don’t understand the values printed by the app.
“Generation” on the initial screen/graph seems to be the overall solar producted enery.
But what is “Today” next to it? (6342.1kWh on my graph for 4058.4kWh Generation).

Same question when I go to the “View cost” page (up right link from the initial screen).
Generation seems to be the overall money made by solar (€689.94).
But what is “Today” (€474.08)?

When going to the "View energy graph, I’ve seen that I need to wait a couple seconds for the data to refresh after the page updates to the new graphes.

But what are the figues above the graph (NOW, GENERATION, SELF-CONSUMPTION, GENERATION, TODAY)? They don’t change when changing the timeframe (week, month, year).

Same question when going to the “View Cost” page from there.
What are NOW, GENERATION, GENERATION and TODAY?

Also, could someone explain me the point of “set the power value now” code in this app?
How does it work and why?