"change spreads by touch"............as soon as history initially changes, the rest of the universe is unchanged except for where it came into contact with the changed situation. Ie, if Ben had died as a child, this would not immediately change Jack or Kate - but it would affect the people Ben knew as a child (and if any of them later encountered Jack or Kate, then those two would change). Or, if in season 4, Megan had proposed to Larry, that would not immediately alter the outcome of elections in China or the UK (but if the proposal followed the next category, it would alter them, actually), but it would affect Colby and Charlie and Amita (impetus to propose there?)
"instant butterflies"........as soon as history initially changes - Donna Noble goes left instead of right, Juliet kicks Kate off the sub, or prison escapee Colby Granger gets arrested in the subway* - everything in the universe changes from the history we knew. This differs from the previous category because, in this, there is no connection between anything: Colby is arrested, and a minute later, a tourist is suddenly shot in Kazakhstan.
"in the bubble"...........even if the rest of the universe changed a while ago, this area hasn't changed from the history we know. This is an extreme cousin of "change spreads by touch"...think of Australia: until it was "discovered" in the late 1700s, was it affected by the Spanish Reconquesta or the English Roundheads and the wars either were involved in? not sure of what a fandom version of a bubble would be - maybe the US lost the Pacific War, but southern California is the same as it is in our history?
* = yes, reference to 4.01