Hi Knelly555,
I'm not an estate agent but I am a property investor from the UK (now in Australia).
I found several sites with property glossaries so you can take your pick...
Property Glossary
Glossary of Terms
http://www.estateagents123.com/gloss...erty_terms.php
Property - Glossary of Terms
Freehold is when you own the building and the land underneath it.
Leasehold is the right to live in a property for a set amount of time. This tends to apply to apartments although it is now popular for some apartments to share the freehold so that the owners have more control. When buying an apartment you always need to know the length of the lease since as the lease gets shorter the value of the property can go down since there is a cost to renewing a lease.
I've not heard of chain forward although I know chain free.
The chain refers to chain of people involved in a house sale that are dependent upon each other. For example house C may only be sold when both house B and house A are sold and they all have to complete on the same day.
If house sale B fell through then that would affect the whole chain.
Chain free is when someone is buying and has nothing to sell. They are a valuable commodity because they end (or start

) the chain. For example an ideal situation is that someone is buying my house that has been pre-approved for a mortgage, and has nothing to sell so that I'm not at the mercy of other house sales.
I hope that helps,
Karen