Micro SD card
The external memory of your mobile phone, is made of a small memory card. The most used model of memory card is the Micro SD one.
Depending on the capacity of your card, you can store on it your favorite songs, photos, videos, documents and others.
The memory card has the role of expanding your internal memory of the mobile phone, allowing you to put a lot of data.
Depending on the memory card you use, you can put it into an adapter, and then use it to transfer songs, photos, videos, etc. from your card to your computer. So, the memory card will have the same role as an memory stick. The difference between the memory card and the memory stick is the size, and that the card can be used for mobile phones while the stick cannot.
Some mobile phones can save the contacts and the messages you have on your sim card or in your phone internal memory.