st.write('Count = ', st.session_state.count)
```
As you can see in the above example, pressing the Increment button updates the count each time.
Example 2: Session State and Callbacks
Now that we've built a basic Counter app using Session State, let's move on to something a little more complex. The next example uses Callbacks with Session State.
Callbacks: A callback is a Python function which gets called when an input widget changes. Callbacks can be used with widgets using the parameters on_change (or on_click), args, and kwargs. The full Callbacks API can be found in our Session State API Reference Guide.
```python
import streamlit as st
st.title('Counter Example using Callbacks')
if 'count' not in st.session_state:
    st.session_state.count = 0
def increment_counter():
    st.session_state.count += 1
