This component does various setup tasks needed by most other components in SCS. You won't directly notice what it does, but it fixes a few bugs and extends the game's capabilities to allow the rest of SCS to function correctly. (For experts: among other tasks, it installs Detectable Spells and (on non-BGEE Windows installs) ToBEx, makes magic items detectable, modifies weapons so that the script engine can detect their enchantment level, fixes the bugged Spell Shield spell, reconfigures area-effect spells so that Mirror Image doesn't block them, and prevents casting from being disrupted by zero-damage attacks.)
(Advanced users who find my mods slightly too good at detecting items may wish to experiment with setting AI_Does_Not_Detect_Items to 1 in stratagems/stratagems.ini; this isn't recommended, though.)