This is an attempt to shed some light on the variety of nouns introduced by Lab Management, as is common with every new product. The list below primarily contains terms that you would encounter while accesing the sdk exposed by Lab Management ie this targets developers.

SCVMM : System Center Virtual Machine Manager aka VMM

Host Group [HG] : A logical entity which groups a set of hosts. Host groups can be hierarchial in nature and hosts cannot be shared across disjoint host groups.

Library Server : A host which exposes UNC shares that would be used as resources to be managed by the SCVMM server.

Library Share [LS] : A subset of the UNC paths on library servers that are explicity added to the SCVMM server

Integration Components : A set of drivers installed on virtual machines to provide better integration with the host housing the virtual machine.

Virtual Network : A virtual network allows you to configure various network topologies for virtual machines and hosts. Virtual networks can be external/internal/private

Network Location : Each physical network adapter has network location associated with it eg. This is something new introduced in Vista.

TeamProjectCollectionHostGroup [TPCHG] / TeamProjectCollectionLibraryShare [TPCLS] : Logical lab entities at the TeamProjectCollection level which map onto related SCVMM Host Groups and Library Shares. You would want to have a 1-1 mapping of a library share or host group on SCVMM to a TPCLS and TPCHG. It is not recommened to have multiple TPCLS/TPCHG objects mapping to the same LS/HG objects on SCVMM.

For a given project collection you can add multiple such TPCHGs and TPCLSs

TeamProjectHostGroup [TPHG] / TeamProjectLibraryShare [TPLS] : Logical entities at the TeamProject level which map onto TPCHG and TPCLS objects. Think of these objects being contained within their corresponding TPC objects

For a given project you can add multiple such TPHGs and TPLSs

Bird's View : The above objects are essentially a hierarchy of logical objects, one contained within another at most times, as shown here: 

MyCollection {TeamProjectCollection}

MyTPCHG1 {TeamProjectCollectionHostGroup -> internally maps to HG1 on SCVMM}

MyTPCLS1 {TeamProjectCollectionLibraryShare -> internally maps to LS1 on SCVMM}

MyProject {TeamProject}

MyTPHG1 {TeamProjectHostGroup -> internally mapping to MyTPCHG1 and therefore to HG1 on SCVMM}

MyTPLS1 {TeamProjectLibraryShare -> internally mapping to MyTPCLS1 and therefore to LS1 on SCVMM}