**What Is Meant by Bubble Sort in Data Structure?**

Bubble sort is a simple sorting algorithm that works by repeatedly stepping through a list of elements to be sorted, comparing each pair of adjacent elements, and swapping them if they are in the wrong order. This process is repeated until the entire list is sorted.

The name “bubble sort” comes from the way smaller elements gradually “bubble” to their correct positions as they are compared and swapped with adjacent elements.

## How Does Bubble Sort Work?

The basic idea behind bubble sort is to repeatedly iterate over the list and compare adjacent elements. If the elements are out of order, they are swapped.

This process continues until the list is completely sorted.

Here’s a step-by-step breakdown of how bubble sort works:

**Step 1:**Start with an unsorted list of elements.**Step 2:**Compare the first element with the second element. If the first element is greater than the second element, swap them.**Step 3:**Move to the next pair of adjacent elements and repeat step 2. Continue this process until you reach the end of the list.**Step 4:**Repeat steps 2 and 3 for each pass over the entire list until no more swaps are needed.

## An Example

To better understand how bubble sort works, let’s go through a simple example:

```
def bubble_sort(arr):
n = len(arr)
for i in range(n):
for j in range(0, n-i-1):
if arr[j] > arr[j+1]:
arr[j], arr[j+1] = arr[j+1], arr[j]
return arr
# Example usage
my_list = [9, 2, 5, 1, 7, 6]
sorted_list = bubble_sort(my_list)
print(sorted_list)
```

In this example code snippet, we have an unsorted list of numbers: [9, 2, 5, 1, 7, 6]. The bubble_sort function implements the bubble sort algorithm to sort the list in ascending order.

After applying the bubble sort algorithm to our list:

__Pass 1:__[2, 5, 1, 7,**6**,**9**] (Swapped elements: 9 and 6)__Pass 2:__[2,**1**,**5**,**6**,**7**,**9**] (Swapped elements: 5 and 1)__Pass 3:__[**1**,**2**,**5**,**6**,**7**,**9**] (No swaps needed)

The final sorted list is [1, 2, 5, 6, 7, 9]. As you can see from the example above, bubble sort compares adjacent elements and swaps them if necessary until the list is sorted.

## The Time Complexity of Bubble Sort

Bubble sort has a time complexity of O(n^2) in the worst and average case scenarios. This means that as the number of elements to be sorted increases, the time it takes to sort them using bubble sort grows quadratically.

Although bubble sort is not efficient for large datasets, it is still useful for small lists or already partially sorted lists due to its simplicity and ease of implementation.

## Conclusion

Bubble sort is a simple sorting algorithm that repeatedly compares adjacent elements and swaps them if they are in the wrong order. While it may not be the most efficient sorting algorithm for large datasets, it can be useful for small lists or partially sorted data. Understanding bubble sort helps build a foundation for understanding more complex sorting algorithms.

Now that you have a better understanding of what bubble sort is and how it works, you can explore other sorting algorithms and their implementations in different programming languages.