Controlled vs. Information Service: The Critical Distinction

The most important distinction a student pilot must grasp is the difference between receiving a clearance and receiving information.
When you call "Linz Tower, D-EHGH, ready for takeoff," and Linz Tower responds "D-EHGH, cleared for takeoff runway 27," that is a clearance. The tower has taken responsibility. It has checked that the runway is clear and that no approaching traffic will hit you. The tower is liable for your safety during that takeoff. You may proceed with confidence.
When you call "Wels Radio, D-EHGH, holding point runway 27, ready for departure," and Wels Radio (the AFIS station) responds "D-EHGH, wind 280 degrees 3 knots, runway 27, take off at own discretion," that is information. The station has told you the wind and the runway, but it has NOT checked whether other traffic is on approach. The station has NOT cleared you. The responsibility for safe separation remains yours. "At own discretion" is a legal phrase meaning the station provides no protection and takes no responsibility.
The consequence: at AFIS fields, you must look outside and ensure the approach is clear before you take off. At controlled fields, you may take off once cleared, confident the tower has done this check for you.
At unattended fields, there is no station at all. You must look outside and ensure absolute safety yourself. You broadcast to any aircraft on frequency, but you cannot assume anyone is listening.