Horizontal bar diagram is a type of chart used to represent and compare data in a horizontal manner. It is a graphical representation of data in which bars are plotted horizontally to represent the data values. This type of chart is particularly useful for displaying the distribution of data over time or across different categories.

Uses of Horizontal Bar Diagram:

1. Qualitative Data: Horizontal bar diagram is used to represent qualitative data. This type of data is non-numeric and cannot be measured or counted. For example, data related to gender, race, religion, etc. can be represented using a horizontal bar diagram.

2. Data Varying Over Space: Horizontal bar diagram is also used to represent data that varies over space. This type of data is geographical in nature and can be represented using a map. For example, data related to population, GDP, etc. can be represented using a horizontal bar diagram.

3. Quantitative Data: Horizontal bar diagram is also used to represent quantitative data. This type of data is numeric and can be measured or counted. For example, data related to sales, revenue, expenses, etc. can be represented using a horizontal bar diagram.

4. (a) or (b): Horizontal bar diagram can be used to represent either qualitative or data varying over space.

Advantages of Horizontal Bar Diagram:

1. Easy to Interpret: Horizontal bar diagram is easy to interpret as it presents data in a clear and concise manner.

2. Comparison: Horizontal bar diagram is useful for comparing data across different categories.

3. Visually Appealing: Horizontal bar diagram is visually appealing and helps to draw the attention of the viewer.

4. Readability: Horizontal bar diagram is easy to read as the bars are plotted horizontally, which makes it easy to compare data values.

In conclusion, horizontal bar diagram is a versatile chart that can be used to represent a wide range of data. It is particularly useful for representing qualitative data, data varying over space, and quantitative data. It is visually appealing, easy to interpret, and useful for comparing data across different categories.