Computers are much more complicated than the typewriters or adding machines they often replace, which means there are more ways they can fail. And when they fail, it can mean that your programs or data are lost. There are ways to protect yourself. Most important is to make backup copies of important documents. The simple backup programs which come with most computers can make making copies of important files on diskette.
Some users install tape drives on their computers.
Tape is better than diskette because a single tape can store 250 megabytes of data or more. To back up 250 megabytes of information on diskettes you might have to use more than 100 diskettes, each of which will have to be put in and taken out of the computer by hand. Another risk is that someone might look at or steal your data, particularly if you use a portable computer. See whether your software permits you to encrypt your data or protect it with a secret password. Then, even if someone gets your file, they will be unable to read it.