Arrays vs Lists

[Mike McManus]

I have seen a lot about arrays lately here. So I am wondering.

1. Why or when is an Array better than a list?
2. When is a multidimensional Array better than a variable made up of 
multiple lines with a list on each line?

It seems very simple to address item 2 of line 4 or some such. Or to 
just repeat "for each line". Not sure what the effective result is of 
either creating it as an array or splitting it into an array.

Then there was the whole discussion of large text blocks or files put 
into an array, which seemed very interesting considering my need to 
read in multimegabyte files and do some replacing, and combining of 
files. Then writing them out to a new file.  Something that is 
currently very slow. But I will have to consider this as I get further 
into rewriting the project.