What's the Difference Between DVD-RAM and DVD-ROM?

Generally, DVD RAM is widely used to back up and archive computer data files.

DVD ROM, on the other hand, is popular among home users for the same purpose, is the preferred choice to store movies or audio presentations.

For the contents of a DVD-ROM to be read, laser of a different wavelength is required compared to other DVD formats. 

DVD-ROM is preferred owing to its comparability with the majority of set top DVD players which don't support DVD-RAM. 

DVD-RAM is also not supported by  computer DVD-ROM drives.

Once data is recorded into a DVD-ROM it could only be read. So, if you've recorded a movie in a DVD-ROM, you would not be able to delete the movie by inserting it into your computer DVD drive. 

In the case of  DVD-RAM, data could be rewritten many times over. That explains why it's favoured for data storage. You can store data in it, erase the data later and save new data in it.

Why DVD-RAM Favoured for Data Storage
Another reason why DVD-RAM is favored for data storage is its lifespan. 

It is expected to last a maximum of 30 years and sustain up to 100,000 rewrites. 

Also, the write speed for DVD-RAM is higher and produces more accurate data copying and transfer compared to DVD-ROM. In other words, there is not likely to be any data loss or errors during the writing process.

 In situations where sensitive data needs to be backed up, updated  and stored for a long period of time, DVD-RAM is the automatic choice.

DVD-ROM is suitable for storing data that doesn't need to be updated. It's ideal for storing data that could not be tampered with by those consuming it.

The other important difference is most DVD-RAM drives have the ability to read DVD-ROM discs. 

But a DVD-ROM drive can't read a DVD-RAM disc because data is stored in an optical cartridge.