Heap uses nearly the same session definition as other analytics solutions, such as GA4. You can use these tools as a starting point for understanding what your session volume may look like in Heap.
For a comprehensive, feature-based comparison of Heap to other tools, including Amplitude, Fullstory, Google Analytics, Mixpanel, Pendo, and Quantum Metric, see our Compare page.
For more information on how sessions fit into Heap's data hierarchy, see Heap's Data Model.