SAP == Software Aus Pakistan
Also massively expensive package for CRM, warehousing, etc. etc..
SAP consultants love it, almost everyone else hates it for being inflexible, overexpensive, hard to use, etc. etc..
SOA == Service Oriented Architecture.
The latest hype and buzz, replacing and expanding on the previous hype which was (unless I missed one) MDA.
B2B == Business 2 Businesss.
Software used for transactions between corporations. Effectively often used to mean overly expensive massive applications that noone knows what they do but they are the stepping stone to higher management for project managers
Legacy systems == mainframe applications
Also, any old software or databases which you still need to support in your new application which will itself be a legacy system as soon as someone thinks up a new hype to replace it with another architecture.
Grid computing == one of those hypes.
The idea that many computers working together can do more work cheaper than one large computer working alone.
Also known as distributed computing, people have been doing it for decades but until it's a hype it doesn't officially exist so don't tell anyone