Plain English Meaning
A zoomed-in VFR map of the airspace around a major, busy airport. Because everything is shown at a larger scale, the picture is more detailed and easier to read when you're flying near or through complex airspace.
Full Definition
A VFR Terminal Area Chart is a large-scale aeronautical chart, drawn at 1:250,000, that depicts the airspace surrounding the busiest airports in the United States — specifically those designated as Class B airspace. It shows airspace boundaries, altitudes, VFR checkpoints, terrain, obstructions, navigation aids, and airports in greater detail than a Sectional Chart.
Context Anchor
You see TACs during preflight planning and in flight when operating near major airport where a sectional chart may not show enough local detail.