"JUMPSTART" is an installation profile designed to get a site up and running quickly. It creates a Drupal7 site, enables some of the most usefull core and contributed modules while it does not enable some core modules that are enabled on the "standart" installation profile.
It helps for rapid-development, creating sandboxes and of course for every day drupal usage since it saves you some time (eg: it auto enables views).
Contrary to most Installation Profiles, Jumpstart is version agnostic.
This means that it can be used against any version of D7. This is true for
the modules too. The reason that Jumpstart is version agnostic is simple:
By itself it doesn't do much, it simply enables a set of common modules.
NOTE: drupal.org demands a version on each project that is being packaged. So an experienced user might prefer using the profile-only package instead of the one including core.
At the moment Jumpstart enables the following modules (and dependencies):
Colorbox (the .make file also fetches the script)
It doesn't enable comments, toolbar, overlay and several other core modules.
This shouldn't tamper with the users experience in any way though.