Why do we always need to wait for 'launch windows' to get a rocket to space?

Artemis I launch has been ‘scrubbed’ a couple of times now. Why is a launch window so important, and what does scrubbing mean, anyway?

How Things Work: Shuttle Launch Windows, Air & Space Magazine

Why can't a rocket just be 'thrown off' Earth's surface? Launch windows are important

What is a launch window? And why is it needed to get a rocket into space?

Artemis I launch attempt scrubbed due to possible hurricane - ABC News

Weather delays launch of NASA's billion-dollar Psyche mission to Friday – Spaceflight Now

What is the actual aim of SpaceX's Starship space vehicle? - Quora

Why Rockets Launch Vertically - Headed For Space

Tech it to space: Why do we always need to wait for 'launch windows' to get a rocket to space?

NASA Sets Launch Times With Science and Precision

More delays for NASA's astronaut moonshots, with crew landing off until 2026 - OPB

Tech it to space: Why do we always need to wait for 'launch windows' to get a rocket to space?