A push moves **both screens at the same speed in the same direction**. The incoming screen's leading edge is glued to the outgoing screen's trailing edge, so it feels like sliding along one long horizontal strip. The iOS navigation stack (list → detail) is the classic case, and Keynote/PowerPoint also call a slide transition "Push."
Direction carries meaning: entering from the right means "forward / deeper," entering from the left means "back." Keep it consistent. Do not confuse it with **cover (→ cover-transition)**, where the old screen stays put, or **reveal (→ reveal-transition)**, where the new screen stays put.
In CSS, give both screens the same `translateX`. If one moves slower than the other it stops being a push and becomes a parallax effect.
When to use
Use it for hierarchical moves (list → detail, next step). For same-level tab switches a fade is less disorienting than a push.