Fisrt of all, comparing 持っています and もちます would be better, or 持っている and 持つ.
持っています means "something belongs to someone", "someone owns something" or "someone keep having / holding something for the duration (of time).
持つ is for the action
私はたくさんの本を持っています。= I have a lot of books. (These books are mine / belong to me.)
私は一日中、この辞書[じしょ]を持っていました。= I kept having/carrying this dictionary durling the day / all day long.
カギと携帯電話[けいたいでんわ]を持って出かけました。= I left home with my key and cellphone.
*There are more mening in 持つ but I wrote the basic one focusing on the difference you asked.
I hipe this was helpful.