Microsoft Excel is a powerful spreadsheet application with a wide range of features and functions. In addition to the basic functions and commands, there are several important sections, features, and terms to be aware of:

1. Ribbon: The Ribbon is the tabbed toolbar at the top of the Excel window that contains various commands and options. It is organized into tabs, such as Home, Insert, Page Layout, Formulas, Data, Review, and View, each containing related commands.

2. Worksheet: A worksheet is a single sheet within an Excel workbook where you can enter and manipulate data. By default, a new Excel workbook opens with three worksheets, but you can add more as needed.

3. Workbook: A workbook is an Excel file that can contain multiple worksheets. Workbooks are saved with a .xlsx file extension. You can have multiple workbooks open at the same time.

4. Cells: Cells are the individual rectangular boxes in an Excel worksheet where you enter and manipulate data. Each cell is identified by a unique combination of a column letter and a row number (e.g., A1, B2).

5. Columns and Rows: Columns are vertical groups of cells identified by letters (A, B, C, etc.), while rows are horizontal groups of cells identified by numbers (1, 2, 3, etc.).

6. Active Cell: The active cell is the currently selected cell in which you can enter or edit data. It is highlighted with a dark border.

7. Cell Reference: A cell reference is a way to identify a cell by its column letter and row number. For example, A1 is a cell reference for the cell in the first column and first row.

8. Formulas and Functions: Formulas are mathematical expressions you can use to perform calculations on data in Excel. Functions are predefined formulas that perform specific tasks, such as SUM, AVERAGE, and VLOOKUP.

9. AutoSum: The AutoSum button (Σ) is a quick way to add up a range of selected cells. It can be found in the Editing group on the Home tab.

10. Charts and Graphs: Excel allows you to create various types of charts and graphs to visualize data. Common chart types include bar charts, line charts, and pie charts.

11. Named Ranges: You can assign names to specific cell ranges to make formulas and functions more readable and easier to manage. Named ranges are often used in complex worksheets.

12. Data Validation: Data validation allows you to set rules and restrictions on what can be entered in a cell. This helps maintain data accuracy and consistency.

13. Conditional Formatting: Conditional formatting lets you format cells based on specific conditions. For example, you can highlight cells with values above a certain threshold in a different color.

14. PivotTables: PivotTables are powerful tools for summarizing and analyzing large datasets. They allow you to create interactive reports and perform data analysis tasks.

15. Data Tables: Data tables are used to perform "what-if" analysis by changing one or more input values to see how they affect the results of a formula or function.

16. Sorting and Filtering: Excel provides options for sorting data in ascending or descending order and applying filters to easily display specific data subsets.

17. Data Analysis Tools: Excel offers various data analysis tools, such as Goal Seek, Solver, and Scenario Manager, to help solve complex problems and make data-driven decisions.

18. Protecting Sheets and Workbooks: You can password-protect worksheets and workbooks to restrict access and prevent unauthorized changes to your data.

19. Excel Add-Ins: Add-ins are additional features or functionalities that can be added to Excel to extend its capabilities. Examples include data analysis add-ins and third-party tools.

20. Sparklines: Sparklines are tiny charts that can be inserted into individual cells to provide a visual representation of data trends within a cell range.