Reboot   To restart the continuity of a book or character. To reintroduce the character as if s/he is a new character. Typical examples: MAN OF STEEL, the George Perez WONDER WOMAN, DOOM PATROL, BATMAN: YEAR ONE. Sometimes these reboots are done retroactively, as with MoS and B:YO, sometimes they are "in continuity", as with WW and DP

Retcon   Short for "retroactive continuity". This happens when something which works a profound change on the character(s) is introduced retroactively, but without completely rebooting the character(s). Much of Frank Miller's work on DAREDEVIL hinged on retcons. SPIDER-MAN: CHAPTER ONE was retroactive continuity. Superboy was perhaps the earliest retcon.

Continuity   Refers to the continuing backstory of a character, built up over many issues, years and even decades. Often composed in large part of retcons, this is different from...

History ...which refers to the "real world" story of the character(s), dealing with the creators, the way in which the stories were concocted, the publishing history, etc.

Crossover   When a storyline continues from one title to another, either between two or between multiple titles. This can be between two (or more) unconnected titles (unconnected except for sharing the same "universe"), as with the DAREDEVIL/GHOST RIDER crossover that I drew early in my career, or can be between several titles belonging to the same character(s), as with the upcoming SUPERMAN/ACTION/ADVENTURES crossover of which I drew the middle part. (One of the reasons I left AMAZING SPIDER-MAN was that, despite best intentions at the outset, the stories began crossing between the two Spider-Man titles, and I found myself drawing too many first parts without knowing what was in the second.)

Guest Appearance or Team Up   Often erroneously referred to as a "crossover", this is the appearance of character(s) in a title belonging to someone else. Here the character(s) appear, but the storyline is self-contained. The upcoming appearance of the JLA in BLOOD OF THE DEMON is a guest appearance, not a "crossover".

Panels   The individual pictures that make up a comicbook page. Not "frames".

Splash Page or Full Page Splash   The first is usually indicating the opening page of a story, which contains the title and cradits. Since the title and credits can sometimes float around a bit, this is not an absolute. The second, however, refers to any full page illustration which does not contain the title.

Double-Page Spread   Any image or images that cross the fold. This can be one huge panel, or multiple panels.

Speech Balloon or Thought Balloon   Not "bubble".

Trunks   The article of clothing worn by many superheroes around their midsection, usually (tho not always) a different color or shade from the rest of the costume. Not "shorts".

Boots   A collective term for the footwear sported by most superheroes. Sometimes with soles and heels, sometimes not. Batman wears boots -- so do Superman and Spider-Man.

Uniform or Costume   Often used interchangably, they have different meanings. Superman, Batman, Spider-Man and even Iron Man wear "costumes". The Green Lantern Corps (at least as originally portrayed) wear uniforms. The Fantastic Four wear uniforms, as did the original X-Men, who later switched to individualized costumes. (The ringer in this is Captain America, who is the only one who sports his particular outfit, but who should nevertheless be referred to as wearing a uniform.)

Chest Emblem   The design worn by many superheroes on their chests. Not "logo".

Spider-Man   not "Spiderman" or "Spider-man".

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Sounds to me like you see the difference. YEAR ONE and MoS were both set in the past, so that the current issues of the respective titles were affected only as much as the writers and editors wanted them to be. WONDER WOMAN and DOOM PATROL reintroduced the characters, as new characters, wiping out (not "taking over") all previous coninuity.