📊 Tableau – Complete Detailed Notes

Teaching Version • Beginner to Advanced • With Real-Life Examples

1️⃣ What is Tableau?

Tableau is a powerful Business Intelligence (BI) and data visualization tool that helps users analyze raw data and convert it into interactive charts and dashboards.

Simple Definition:
Tableau is a tool that converts numbers and raw data into visual charts so that we can easily understand business performance.

🌍 Real-Life Example

Imagine a retail store owner who has thousands of sales records in Excel. Reading rows is difficult, but in Tableau:

📊 Bar chart → Top products
📈 Line chart → Monthly sales trend
🗺️ Map → City-wise performance

Result: Faster and smarter business decisions.

2️⃣ Tableau Architecture

Tableau connects to data in two main ways:

Connection Type	Meaning	Use Case
Live	Direct connection to database	Real-time banking data
Extract	Snapshot of data stored locally	Student projects, faster performance

3️⃣ Tableau Interface

+----------------------------------+

| Data Pane | Columns | Rows       |

|-----------|-----------------------|

| Filters   |        View           |

| Marks     |                       |

+----------------------------------+

| Sheets | Dashboard | Story       |

+----------------------------------+

🔑 Important Areas

Data Pane: Contains Dimensions and Measures
Columns Shelf: Controls horizontal axis (X-axis)
Rows Shelf: Controls vertical axis (Y-axis)
Marks Card: Controls color, size, label, tooltip

4️⃣ Dimensions vs Measures

Feature	Dimension	Measure
Meaning	Qualitative (text/category)	Quantitative (numbers)
Example	City, Category	Sales, Profit
Purpose	Grouping	Calculation

Memory Trick:
Dimension → Describe
Measure → Calculate

5️⃣ Types of Charts in Tableau

Bar Chart: Best for comparison (Top products)
Line Chart: Best for trends (Monthly sales)
Pie Chart: Best for percentage share
Map: Best for geographical analysis
Tree Map: Best for hierarchical data

6️⃣ Filters in Tableau

Filters help display only required data.

Filter Type	Purpose
Extract Filter	Before data load
Data Source Filter	At source level
Context Filter	Creates subset
Dimension Filter	Filters categories
Measure Filter	Filters numbers

7️⃣ Calculated Fields

Calculated fields allow us to create custom formulas.

Profit Ratio = SUM(Profit) / SUM(Sales)
  

Use Case: Finance team calculates profit margin.

8️⃣ Dashboard in Tableau

A dashboard is a collection of multiple visualizations in one screen.

+--------------------------------------+
| KPI Cards                            |
+------------------+-------------------+
| Sales Trend      | Region Map        |
+------------------+-------------------+
| Category Bar Chart                  |
+--------------------------------------+
  