You only need to download one format of each file. Each has the same contents but use different packaging methods.

File descriptions

train.csv - the training set test.csv - the testing set sample_submission.csv - a sample submission file in the correct format Data dictionary

PostId - ID number of the question PostCreationDate - Date and time the question was asked OwnerUserId - ID number of the question asker OwnerCreationDate - Date and time the question asker's account was created ReputationAtPostCreation - Reputation of the question asker at the time the question was asked OwnerUndeletedAnswerCountAtPostTime - Number of answers (to other questions) that the question asker had written at the time the question was asked Title - Title of the question BodyMarkdown - Body of the question Tag1 through Tag5 - Topical tags applied to the question PostClosedDate - Date and time the question was closed (if it was closed) OpenStatus - 1 indicates open, 0 indicates closed (the response)