Two related ideas
Flexibility generally refers to how far a muscle and surrounding tissues can lengthen. Mobility describes your ability to control movement through a range at a joint. Both can matter, depending on the activity you want to do.
Match the practice to the goal
Gentle stretching may help you work on flexibility, while controlled movements and strength through a comfortable range may support mobility. A warm-up should prepare you for the activity ahead rather than create fatigue.
Consistency beats intensity
A few minutes practiced regularly may be easier to maintain than occasional, aggressive sessions. Avoid forcing a joint into painful positions. A physiotherapist or qualified professional can help when restricted movement affects daily activities.
A thoughtful next step
Use this guide as a starting point, not a rigid rulebook. Consider your own circumstances, look for reliable sources, and seek qualified professional advice when a decision affects your health or safety.