Excel stores data in a grid of cells addressed by column letter and row number (e.g. C5). Formulas start with = and recalculate when inputs change—making spreadsheets interactive calculators and lightweight databases.
Core objects
- Workbook — the .xlsx file
- Worksheet — a tab inside the workbook
- Cell — one intersection; holds value, formula, or format
- Range — rectangular block (e.g.
A1:D10)
Strengths
- Fast what-if analysis for business users
- Visible logic—formulas sit next to data
- Universal export format between teams
Limits
Row limits (~1M), weak collaboration at scale, formula errors propagating silently, and version control pain—graduate heavy ETL to SQL/Python.
Important interview questions and answers
- Q: Cell address C5?
A: Column C, row 5. - Q: Formula prefix?
A: Equals sign=.
Self-check
- Define workbook vs worksheet.
- One strength and one limit of Excel.
Tip: Press Ctrl+` to reveal formulas when auditing someone else's sheet.
Interview prep
- Formula prefix?
Equals sign starts every formula.
- Workbook vs sheet?
Workbook is the file; worksheet is a tab inside it.