From Ardrana

Conjuration and summoning spells bring something to the caster from elsewhere. Conjuration normally produces matter or items from some other place. Summoning enables the caster to compel living creatures and powers to appear in his presence or to channel extraplanar energies through himself.

Note: Conjuration as described here originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.