Linear Search and Binary Search are two important searching techniques used in algorithm design to find a particular element, called the key, from a collection of elements. Both methods have the same basic purpose, but they differ in their working procedure, requirements, and efficiency. Linear Search can be applied to both sorted and unsorted arrays, whereas Binary Search requires the array to be sorted. In Linear Search, the elements are examined one by one from the beginning of the array. The key is compared with each element until a match is found or the end of the array is reached. If the key is found, its position is returned. If the key does not exist in the array, an appropriate message is displayed. Linear Search is simple to implement and does not require the data to be sorted. The following C program implements both Linear Search and Binary Search: ```c #include int linearSearch(int arr[], int n, int key) { int i; for (i = 0; i < n; i++) { if (arr[i] == key) { return i; } } return -1; } int binarySearch(int arr[], int n, int key) { int low = 0; int high = n - 1; int mid; while (low <= high) { mid = low + (high - low) / 2; if (arr[mid] == key) { return mid; } else if (arr[mid] < key) { low = mid + 1; } else { high = mid - 1; } } return -1; } int main() { int arr[100]; int n; int i; int key; int choice; int result; printf("Enter the number of elements: "); scanf("%d", &n); printf("Enter %d elements in sorted order:\n", n); for (i = 0; i < n; i++) { scanf("%d", &arr[i]); } printf("Enter the element to search: "); scanf("%d", &key); printf("\n1. Linear Search"); printf("\n2. Binary