Hugh

Really, your best bet is Google, but I would try and just aim for an overview, where all of those fit into a frame work of Information Technology, such as:-
Voice and Data Networks (not too hard this one, kind of know, but still)
Communications between nodes on a network, and those nodes can range from very large switches to single PCs, and the management and optimisation of those links.

Market Data
Info from companies like Bloomberg which allow the Traders to have up to the second info, to inform their buying/selling decisions

Database & Middleware
Database - Where the information is in logical structured format, such as Oracle, SQL, DB2.
Middleware - a means of passing information from one system to another, often involving validation and transformation; this used to be quite unstructured, but lately tool-sets from companies have become available to produce this, such as Tibco, BEA, IBM and others.

Distributed, Midrange and Mainframe
Types of Computing Systems, but the terms are merging more and more, as midrange become as powerful as some mainframes, but in summary, Distributed is where the processing is shared amongst a number of machines, Midrange is what the name implies, medium sized machines, and Mainframe are the big mothers that do heavy processing.

Underlying support including; Problem and Change Management; Risk and Project Management; Financial and Client Relationship Management.
These are just too long to explain (succinctly) in a forum, but I will try -
Problem Management - assessing and managing and resolving any issues that arise within a system or service, and communicating those issues and resolutions.
Change Management (which should include Capacity and Configuration Management) - assessing and manageing the impact of any changes to a system or service.
Risk Management (which includes Issue and Dependency Management) - assessing, managing and mitigating any issues/risks/dependencies which may affect the work you are undertaking.
Project Management - agreeing deliverables, resources, budgets, timescales, and communicating these and managing them to post-project review.
Financial Management (also known as budget management)
Client Relationship Management (also known as account management, or it could be CRM, which is Customer Relationship Management, which is another beast altogether). Talking to the customer, finding out their requirements, taking that info back to the team/suppliers, and agreeing a solution that meets their requirements (in an ideal world). It's about communication and managing expectations, but also knowing their business.

Hope that helps.