other storage is taking up 40gb on new phone, but on my old phone it only took up sbout 6 and i have the same amount of storage on both iphones, however on my new iphone the other storage keeps growing and i have less storage taken up by apps/pics

other storage is taking up 40gb on new phone, but on my old phone it only took up about 6gb (its still functioning ) and i have the same amount of storage on both iphones, however on my new iphone the other storage keeps growing and i have less storage taken up by apps/pics/videos, how can I minimize the other storage and also is there a way to purchase more iPhone storage or would I have to get a new phone?