Come over this nice definitions of Richard Hundhausen about that terminology in SCRUM and TFS. Which I found very useful, so maybe you like to check that out as well?

Scrum Concept

Visual Studio Concept

Team

Team Foundation Server security groups

Definition of Done

Wiki entry or document on the portal

Product

Team Project

Product Backlog

Product Backlog shared query or Backlog page on TWA

Product Backlog Item

PBI or Bug work item

Acceptance Criteria

Acceptance Criteria field and (optionally) associated Test Case work item(s)

Release

Iteration Path (high level)

Release Plan

Backlog page on Team Web Access (w/ Forecast tool)

Sprint

Iteration Path (low level)

Sprint Dates

Iteration start and end dates

Sprint Goal

Wiki entry or document on the portal

Sprint Backlog

Sprint Backlog shared query or Backlog & Board pages on TWA

Task

Task work item

Burndown and Velocity

Release Burndown, Sprint Burndown, and Velocity reports and charts on TWA

Impediment

Impediment work item

Retrospective

Wiki entry or document on the portal