diff --git a/STL.cpp b/STL.cpp
new file mode 100644
index 000000000..7868d3212
--- /dev/null
+++ b/STL.cpp
@@ -0,0 +1,325 @@
+#include<bits/stdc++.h>
+#include<vector>
+#include<array>
+#include<deque>
+#include<list>
+#include<stack>
+#include<queue>
+#include<set>
+#include<map>
+using namespace std;
+int main()
+{
+	cout<<endl<<endl<<endl<<"VECTORS"<<endl<<endl<<endl;
+    vector<int>v1; //syntax for declaring a vector
+    v1.push_back(1); //enter a value in vector
+    v1.push_back(2);
+    v1.push_back(3);
+    v1.push_back(4);
+    cout<<"values of  v1--"<<endl;
+    for(int i=0;i<v1.size();i++) //method1 to output the values of vector
+    {
+    	cout<<v1[i]<<endl;
+	}
+	v1.pop_back(); //this function deletes the last value inserted in the vector
+	cout<<"after popping"<<endl;
+	for(auto member:v1)  //method2 to output the values of vector
+	{
+		cout<<member<<endl;
+	}
+	vector<int>v2;
+	v2={10,20,30}; //another method of inputing values in vector
+	cout<<endl;
+	cout<<"values of v2--"<<endl;
+	for(auto member:v2)
+	{
+		cout<<member<<endl;
+	}
+	cout<<endl;
+	swap(v1,v2); //this function swaps the values btw two vectors
+	cout<<"after swap function--"<<endl;
+	cout<<"values in v1-- "<<endl;
+	for(auto member:v1)
+	{
+		cout<<member<<endl;
+	}
+	cout<<"values in v2-- "<<endl;
+	for(auto member:v2)
+	{
+		cout<<member<<endl;
+	}
+	cout<<endl;
+	vector<int>v3;
+	v3={6,4,10,8};
+	cout<<"values of v3 before sort function--"<<endl;
+	for(auto member:v3)
+	{
+		cout<<member<<endl;
+	}
+	sort(v3.begin(),v3.end()); 
+	//this function sorts the values of the given vector in accending order (by default) 
+	//to sort in another way give condition using another iteration in the function **see yt for help
+	cout<<"values of v3 after sort function-- "<<endl;
+	for(auto member:v3)
+	{
+		cout<<member<<endl;
+	}
+	cout<<endl<<"capacity of the vector v3-- "<<v3.capacity()<<endl; //gives the capacity of the vector
+	cout<<"\n size of the vector v3-- "<<v3.size()<<endl; //gives the no of elements present in the vector
+	cout<<endl<<"1st element of the vector v3-- "<<v3.front()<<endl; //gives the 1st element in vector
+	cout<<"last element of vector v3--  "<<v3.back()<<endl; //gives the last element in vector
+	cout<<"after erasing the 1st value of v3..."<<endl;
+	v3.erase(v3.begin());//erases the 1st value
+	for(auto member:v3)
+	{
+		cout<<member<<endl;
+	}
+	v3.clear();//clears the vector
+	cout<<endl<<"after clearing vector v3 and printing the values..."<<endl;
+	for(auto i:v3)
+	{
+		cout<<endl<<i;
+	}
+	//v.erase(v.begin()+6);
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"PAIR"<<endl<<endl<<endl;
+	pair<int,char>p1; //syntax to declare a pair
+	p1.first=17; //syntax to declare the 1st element of the pair
+	p1.second='s'; //syntax to declare 2nd element of the pair
+	cout<<endl<<"the values of pair"<<endl<<p1.first<<endl<<p1.second<<endl; //syntax to give output of the pair
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"ARRAY"<<endl<<endl<<endl;
+	array<int,5>arr={1,2,3,4,5}; //implementation of int type array of size 5
+	cout<<"1st element -- "<<arr.front()<<endl;
+	cout<<"last element-- "<<arr.back()<<endl;	
+	if(arr.empty()==0) //to check array empty or not if not gives 0 if empty gives 1
+	{
+		cout<<endl<<"array not empty.."<<endl;
+	}
+	cout<<endl<<"size of the array-- "<<arr.size()<<endl; //gives the size of the array
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"DEQUE"<<endl<<endl<<endl; 
+	deque<int>d;
+	d.push_back(2); //inputs value at back
+	d.push_back(1);
+	d.push_back(3);
+	d.push_front(4); //inputs value at front
+	cout<<endl<<"outputing the values of deque-- ";
+	for(auto i:d) //1st method of outputting
+	{
+		cout<<endl<<i<<endl;
+	}	
+	d.pop_back(); //pops the last value
+	int dsize=d.size(); //gives the size of the deque
+	cout<<endl<<"output after popping back.."<<endl;
+	for(int i=0;i<dsize;i++) //2nd method of outputting
+	{
+		cout<<d[i]<<endl;
+	}
+	d.pop_front(); //pops the first value
+	cout<<endl<<"output after popping front.."<<endl;
+	for(int i=0;i<dsize;i++) 
+	{
+		cout<<d[i]<<endl;
+	}
+	d.erase(d.begin(),d.begin()+1); //erases from 1st value to value after it
+	cout<<endl<<"after erase function..."<<endl;
+	for(auto i:d) 
+	{
+		cout<<endl<<i<<endl;
+	}
+	d.empty();//empty's the deque
+	cout<<endl<<"after emptying the dequeee..."<<endl;
+	for(auto i:d) 
+	{
+		cout<<endl<<i<<endl;
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"LIST"<<endl<<endl<<endl;
+	list<int>l; //implementing list
+	l.push_back(2); //enter the value at last
+	l.push_back(1);
+	l.push_front(0); //enter value at front
+	cout<<endl<<"values in list..."<<endl;
+	for(auto i:l) //output method
+	{
+		cout<<endl<<i<<endl;
+	}
+	l.pop_back(); //pops the last value
+	cout<<endl<<"after popping back..."<<endl;
+	for(auto i:l)
+	{
+		cout<<endl<<i<<endl;
+	}
+	l.pop_front(); //pops the 1st value
+	cout<<endl<<"after popping front..."<<endl;
+	for(auto i:l)
+	{
+		cout<<endl<<i<<endl;
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"STACK"<<endl<<endl<<endl; //works in lifo algorithm
+	stack<int>st;
+	st.push(2);
+	st.push(0);
+	st.push(7);
+	st.push(25); //last in
+	int stsize=st.size(); //gives size of stack
+	cout<<"\n size of stack--- "<<stsize<<endl;
+	cout<<"\n outputing the values...";
+	for(int i=0;i<stsize;i++) //1st method of output
+	{
+		cout<<endl<<st.top()<<endl;
+		st.pop(); //first out
+	}
+	if(st.empty()==true)
+	{
+		cout<<endl<<"stack is empty now"<<endl;
+	}
+	st.push(2);
+	st.push(0);
+	st.push(7);
+	st.push(25);
+	cout<<endl<<"output 2nd method..."<<endl;
+	while(st.size()!=0) //2nd way of output
+	{
+		cout<<endl<<st.top()<<endl;
+		st.pop();
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"QUEUE"<<endl<<endl<<endl; //same as stack just works in fifo algorithm
+	queue<int>qu;
+	qu.push(23);
+	qu.push(67);
+	qu.push(46);
+	qu.push(65);//first in 
+	qu.pop(); //first out
+	cout<<"\n front-- "<<qu.front()<<endl;//gives the value at front
+	cout<<"\n back-- "<<qu.back()<<endl;//gives the value at back
+	while(qu.size()!=0) //gives the size
+	{
+		cout<<endl<<qu.front()<<endl;
+		qu.pop();
+	}
+	qu.empty();//deletes the queue
+	cout<<endl<<"after emptying queue.."<<endl;
+	while(qu.size()!=0) 
+	{
+		cout<<endl<<qu.front()<<endl;
+		qu.pop();
+	}
+	if(qu.empty()==true)
+	{
+		cout<<endl<<"queue is empty now.."<<endl;
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"PRIORITY QUEUE"<<endl<<endl<<endl;
+	priority_queue<int>max; //implementation of priority queue prints value from higher to lower
+	max.push(35);
+	max.push(87);
+	max.push(100);
+	cout<<"prints in decessending order..."<<endl;
+	while(max.size()!=0)
+	{
+		cout<<endl<<max.top()<<endl;
+		max.pop();
+	}
+	priority_queue<int,vector<int>,greater<int>>min; //implementation of priority queue prints value from lower to higher
+	min.push(100);
+	min.push(35);
+	min.push(87);
+	cout<<"prints in acessending order..."<<endl;
+	while(min.size()!=0)
+	{
+		cout<<endl<<min.top()<<endl;
+		min.pop();
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"SET"<<endl<<endl<<endl;//gives us sorted order (acescending) and only unique values
+	set<int>set1; //implement 
+	set1.insert(12); //inserting values
+	set1.insert(12);
+	set1.insert(12);
+	set1.insert(6);
+	set1.insert(0);
+	set1.insert(12);
+	set1.insert(4);
+	for(auto  i:set1)
+	{
+		cout<<i<<endl;
+	}
+	//
+	//
+	//
+	//
+	//
+	//
+	//
+	cout<<endl<<endl<<endl<<"MAP"<<endl<<endl<<endl;
+	map<int,char>map1; //implement of map having int type pointer and char type value
+	map1[2]='a';
+	map1[1]='b';
+	map1[3]='c';
+	map1[1]='b';
+	map1[1]='d';
+	map1[2]='z';
+	cout<<"output of pointers in map..."<<endl;
+	for(auto i:map1)
+	{
+		cout<<i.first<<endl; //i.first prints the pointers in sorted order
+	}
+	cout<<"output of values in map..."<<endl;
+	for(auto i:map1)
+	{
+		cout<<i.second<<endl; //i.second prints the values in sorted order
+	}
+    return 0;
+}