# Line Definition

In **Mathematics**, a line is a **1D figure** that doesn’t have any **endpoint**. It is formed by **joining** multiple **points** extended in **opposite** directions. All points that are being joined to form a line must be **collinear**.

**Note:**

Read about **Collinear Points** here.

Lines have great **importance** in one of the most studied and important **fields** of **Mathematics** i.e. **Geometry**. It is used to **form multiple geometrical shapes** like a **triangle**, a **rectangle**, and a **square**.

**Table of Contents**

A **small part** of any **line** is termed a **line segment**. It is a particular section of the line that has **endpoints**. In simple words, we can **draw** multiple **line segments** from a single line.

**Note:**

You can read about a line segment here in detail.

## Types of lines

Depending on the direction, a line has multiple types. Here we have listed some of the most common types of lines.

### Horizontal lines

A line that extends in the **horizontal direction** or is **parallel** to the **x-axis** will be called a horizontal line.

**Note:**

Read about the **Horizontal line** here.

### Vertical lines

All those lines that extend from **top to bottom** or are **parallel** to the **y-axis** will be termed vertical lines.

**Note:**

Read about **Vertical lines** here.

### Perpendicular lines

If **two lines** meet or intersect each other at an angle of **90 degrees**, they will be called perpendicular lines.

**Note:**

Read about Perpendicular lines here.

### Parallel lines

**Two or more lines** that **keep extending** side by side and **never touch** each other are called **parallel lines**. These lines never meet and make an angle of **0 degrees** with each other.

**Note:**

Read about Parallel lines here.

### Fun Facts about a Line

- A
**line**has no**endpoints**. **A line**is formed by**joining**multiple points**extended**in**opposite directions**.- All
**geometrical shapes**(except circles) are made by**joining lines**. - The
**simplest figure**formed by**joining lines**in**Geometry**is**Triangle**(Three Lines).

### FAQ's

**Are line and line segments the same?**

No line segment is a particular section of the whole line. We can say that line is a complete figure while a line segment is a particular part of that figure.

**Does a line have thickness?**

No, a line has no thickness that’s why it is called a 1D figure.

**Does a line have endpoints?**

No, a line has no endpoints but it keeps extending in opposite directions.

**What is the major difference between a line and a line segment?**

A line is a whole figure while a line segment is a particular section of that figure.

**Can we draw a line with an endpoint?**

Yes, we can draw a line with an endpoint but it will not be termed a line. Such a line will be termed a Ray instead of a line or a line segment.