Numbers in the "Recent Changes" list

[Socob]

First of all, hello to everyone!
I've recently signed up on Bulbapedia and after reading through the guides, I'm left with merely a single question. Looking at the Recent Changes, I discovered a number in brackets whose existance, let alone its meaning doesn't seem to be explained anywhere. I'm talking about these:

# (diff) (hist) . . m Pokémon Made Simple‎; 20:35 . . (+17) . . Zesty Cactus (Talk | contribs)
# (diff) (hist) . . Dawn's Piplup‎; 20:33 . . (+38) . . Kenji-girl (Talk | contribs) (Undo revision 825154 by J-J-M (Talk) Again, was there any proof that the Marill was female. I think not.)
# (diff) (hist) . . Rhyperior (Pokémon)‎; 20:33 . . (+118) . . Dragonrider0192 (Talk | contribs) (→Trivia: )

I'd be grateful if someone could explain them to me, as I'm unable to make any sense of them. Also, as always, I'm sorry if I'm missing something completely obvious here.

 

[evkl]

It's the number of bytes added or subtracted to a given article with every edit.

 

[Jioruji Derako]

It's the number of bytes added or subtracted to a given article with every edit.

And in layman's terms, it tells you how many characters were added or subtracted.
(for example, if I edited my page from "Jioruji" down to "Jio", it would say -4 in the edit summary.)

Geo - a.k.a. Jio Derako

 

[Socob]

Thank you very much for your answers. Now that I know it it seems painfully obvious...

One more thing: I assume bold text just indicates a "big" change to an article, e.g. more than 500 bytes or something? And, similarly, gray text signifies no change at all?

 

[RexRacer]

you got it.