Sheet A sheet is a singular chart or map in Tableau.
Dashboard A dashboard is a canvas for displaying multiple sheets at a time and allowing them to interact with each other.
Workbook A workbook is the entire Tableau file containing your sheets and dashboards.
Measure A variable from the dataset that is meant to be aggregated. (This means it should be a number that it makes sense to do math with sum, average, and so on.) Measures are often continuous data. Examples include GPA, sales, quantity, quota, height, and salary.
Dimension A categorical variable from the dataset that is used to slice and dice the data into different categories. Dimensions are often discrete data. Examples include country, gender, student ID, and name.
Filter A filter is used to limit what data is being displayed on the sheet. Visible controls for a filter on a sheet or dashboard are called Quick Filters.
Tooltip Tooltips are text boxes that appear when hovering over a mark on a sheet in order to give more information. The text and text formatting in them are easily edited through the Marks card.
Marks card The Marks card is the tool used to create a sheet that controls most of the visual elements in a sheet. Using the Marks card, you can switch between different chart types (bar, line, symbol, filled map, and so), change colors and sizes, add labels, change the level of detail, and edit the tool tips.
Rows and Columns Shelves The Rows shelf and the Columns shelf is where you determine which variables will go on what axis. Put data you want displayed along the X-axis on the Columns shelf and data you want displayed on the Y-axis on the Rows shelf.