-----------------------
std::vector<int>()
-----------------------
stack address is 1000 (metadata stored here)

std::vector<int> v1;   // v1 is created on stack at address 1000

std::vector<int> v2 = v1;  // Copy constructor is invoked
                           // A new vector is created with the same content as v1
                           // Stored at a different stack address (e.g., 2000)
                           // A new heap allocation is done for the elements

So in the end:

-----------------------
std::vector<int> (v1)
-----------------------
stack address is 1000
heap address (data) is 3000

-----------------------
std::vector<int> (v2)
-----------------------
stack address is 2000
heap address (data) is 4000 (copied from 3000)

And if you modify v1, it will not reflect in v2

-----------------------
std::vector<int>()
-----------------------
stack address is 1000 (metadata stored here)

std::vector<int> v1;   // v1 is created on stack at address 1000

std::vector<int> v2 = v1;  // Copy constructor is invoked
                           // A new vector is created with the same content as v1
                           // Stored at a different stack address (e.g., 2000)
                           // A new heap allocation is done for the elements

So in the end:

-----------------------
std::vector<int> (v1)
-----------------------
stack address is 1000
heap address (data) is 3000

-----------------------
std::vector<int> (v2)
-----------------------
stack address is 2000
heap address (data) is 4000 (copied from 3000)

And if you modify v1, it will not reflect in v2

-----------------------
new std::vector<int>()
-----------------------
Heap address is 1000

auto v1 = new std::vector<int>() // returns start addrees means 1000
auto v2 = v1                     // Points to 1000

So in the end

-----------------------
new std::vector<int>()
-----------------------
Heap address is 1000

It is pointed by both v1 and v2

And if you modify in v1 it will reflect v2 because they pointing to same stuff

-----------------------
new std::vector<int>()
-----------------------
Heap address is 1000

auto v1 = new std::vector<int>() // returns start addrees means 1000
auto v2 = v1                     // Points to 1000

So in the end

-----------------------
new std::vector<int>()
-----------------------
Heap address is 1000

It is pointed by both v1 and v2

And if you modify in v1 it will reflect v2 because they pointing to same stuff

auto v1 = std::vector<int>;
// fill v1
auto v2 = v1;

auto v1 = std::vector<int>;
// fill v1
auto v2 = v1;