Several doubts
 

Dear friends,
I have not one but four doubts. I narrate them hereunder and will be
very glad to get your clarifications on them.

1) What is data journalling?
2) What are atime updates?
3) What are synchronous directory updates?
4) What is a RAM disk and what are its uses?

I will be happy if you can give clarifications with examples. Thanks in advance.

this sounds so so so much like homework.... please don't expect us to you your work for you, these are simple questions which can easily be googled or referenced with course notes if this is indeed homework as it looks like.