How Prism expects the data to be entered

The difference between ordinary and repeated measures ANOVA, is similar to the difference between unpaired and paired t tests. The term repeated measures means that you give treatments repeatedly to each subject.

Repeated measures or randomized block?

The term randomized block is used when you randomly assign treatments within each group (block) of matched subjects.

Imagine that you compare three different treatments. In a repeated measures design, you'd recruit say 10 subjects (or use ten animals) and measure each of the subjects (animals) after each of the treatments. With a randomized block design, you'd recruit ten sets of four subject each, matched for age, gender etc. (or ten sets of four animals, with the four treated at the same time in adjacent cages...).

ANOVA works identically for repeated-measures and randomized block experiments, and Prism always uses the term repeated-measures.

One way? Or two way?

We consider this part of one-way ANOVA, because there really is only one factor, denoted by the data set columns. But you could argue there is a second factor too, subject, because each row represents a different subject (or block). In fact, you'll get the same results if you analyze with two-way ANOVA and one-way repeated measures ANOVA (assuming sphericity).