Di-electric grease is non-conductive and is very good on modern circuit boards. It allows for a clean (isolated) connection and no "cross talk" on circuit boards.

EE guys are usually more concerned with circuit board connections.

http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

The conductive grease is an antioxidant and provides corrosion protection.

http://www.permatex.com/products-2/...atex--copper-anti-seize-lubricant-detail

http://www.specialized.net/Specialized/CP8TB-Thomas--Betts-KoprShield-Compound-8Oz-2265.aspx