What is the difference between "Move" and "Survey System"?

Like if I move to a star, I see all the planets. If I Survey System I see all the stars. To get rid of the question marks I need to survey planet.

Dose selecting survey system make the scout survey each planet on the system?

Moving to a star system lets you see the planets and provides you with basic information about each planet.

Surveying is a more through examination of each planet in the system, it will reveal more details about the planet. Including specials, artifacts, quest related structures and so forth. You may then order a dig if there is something to retrieve.

Surveying can take several turns, you can order a ship to survey a single planet or the whole system automatically. A turn notification is displayed as the survey progresses if it finds anything and once it's completed.

You can order a Survey system to another sector by clicking on any star on the map or the star in the system planet list. The task force / ship will plot a course to move there and survey.