When to use the present participle (or gerund) in French and how is it different to the English gerund (ING-form)?

The French gerund is a verb form that ends with -ant. Just like the ING-form in English, it has various uses.  
First, it can express a progressive action (an action that is taking place/in the process of happening) or a means, just like the ING-form. In this case the gerund follows the preposition en (which can express: when, while: progressive action; by/through: means).  Example:  1. Je n’utilise jamais mon téléphone en conduisant. (I never use my phone while driving.): progressive action.  2. C’est en mangeant que l’on grossit. (It is by/through eating that one puts on weight): means 
Second, the French gerund can also be used to turn verbs into adjectives. Remember that like all adjectives in French, adjectives formed using the gerund will take inflection according to gender and number.  Example:  1. Harry et Ron volèrent la voiture volante. (Harry and Ron stole the flying car.)  Note that you cannot do this as freely as in English, because all French verbs can’t be turned into adjectives. For example, ‘a writing machine’ is ‘une machine à écrire’, NOT ‘une machine écrivante’.  
However, the French gerund cannot be used as an equivalent of the English present/or past progressive tenses. In that case, one has to use the expression: être (conjugated in the right tense/mood/person) + ‘en train de’ + infinitive form of the verb  Example:  1. Je suis en train d’écouter de la musique. (I’m listening to music).  2. Elle était en train de boire son café quand il entra dans la pièce. (She was drinking her coffee when he walked into the room).  
Moreover, the French gerund cannot be used to express actions that will happen in the future, unlike with the English ING-form. In that case, it is best to use Near Future (aller [conjugated in the future tense] + infinitive) or Present as Future tenses (the simple present used to express future actions). Present as Future denotes a less remote action than Near Future.  Example:  1. Je viens [= aller conjugated in the present] chez toi mercredi prochain. (I’m coming to yours next Wednesday). : Present as Future 2. Je vais [= aller conjugated in the future] venir chez toi mercredi prochain. (I’ll be coming to yours next Wednesday). : Near Future  
Finally, you cannot use the French gerund as a noun, unlike in English. You would have to use the infinitive form.  Example: 1. Manger est bon pour la santé. (Eating is good for your health).