مثل is describing the item or gives one of its characteristics; so we can say it is 'same like' مثال is just an example or equivalent but not the same. مثال also can be used in Arabic as a 'symbol' or 'model' (look into the second sentence) على سبيل المثال، مثل المؤمن مثل النحلة1 For example, the believer is same like the bee. 2 هارون مثال للشجاعة Harun is an example for the bravery wish you a happy year full of learning. Safy, a professional Arabic teacher on italki. Update: the answer has been edited based on a comment from sister MG, May Allah reward her with his best, ameen

مَثَل=proverb for example مِثال=

راجعت في المعجم هاتين الكلمتين (مثل و مثال) و قرأت معنى شبيها. هل منكم من يستطع أن يُفهمني الفرق بينهما؟ Here you are the sentence after some tiny corrections