What does it mean that a digital camera has an external memory?

Do I have to buy another gadget to instal this external memory in it, or can I replace the internal by the external card or what? Or do I have to buy a card reader?

No gadget is necessary to use the external memory, its usually a card or stick that is inserted into the appropriate area.

You can download the photos with the cord that came with the camera, however, it might be easier to by a card reader.

See the sites I've mentioned.

It means that the camera takes a memory card (i.e. SD, CF, Memory Stick etc..). The obvious benefit of this is that you can have any size cards you like. And if you are a serious shooter a selection cards. Internal memory would mean the camera also/only has an internal memory, which would be a fixed amount.

Most digital cameras will be external memory only, some have both, very very few have internal only.

You don't have to have a card reader, you can just connect the camera to the PC. But I find it easier as I use different cards and I also find that the card reader is a lot faster.

you have to buy a memory card as extra memory that fits in your camera get bigger byte one so you can take pics as much as you can

internal memory is built into the camera and not a crd that can be removed, external memory is the sd card or compactflash card etc..

for example my camera has a 512mb card but if i take the card out the camera still has 16mb of space to store pictures which is built into the camera not a removable card,
this internal memory usually cant be accessed when there is a card in the camera, (it cant on mine anyway)

All you you need is a Memory Card which expands you internal memory (make sure you buy the correct format) theres plenty to choose from....

all camera come with some memory so you can use it out of the box. canon don't come with internal memory, they come with SDcards, usually 16 or 32MB. Kodak and Sony comes with internal memory, 16 or 32MB of memory, but it's not on a memrory card, it's in the camera. you would need to buy another memory card and put it in the slot(unless you want 10 pic at a time)

they say internal so people don't take back cameras and say there no memory.