Conferences have specific themes and come up fast. Themes are announced at the beginning of the year; then researches go crazy to get their stuff done and written up. Some folks starting their research from scratch. Papers submitted have to fit the theme and often sub-themes of the conference. Conferences peer reviewers are generally given a month to review, which is no time at all. That's a fast turnaround. Then there is extra time for several rounds of revisions by the author, according to feedback from the reviewers. On cutting edge topics, it usually takes twice or three times to get the paper accepted. You are looking at up to 4-5 months to for the process to end. Conferences - everything is super fast to make sure the conference happens on time and is successful. The deadlines are hard and can't be moved. No flexibility in the tight schedule. Journals on the other hand, accept papers anytime of the year, and depending on the topic, may be published as soon as they are approved, or anytime in the future when your topic rolls around. There is no real deadline. Therefore, research can take months (usually years); reviews of journal manuscripts are given much more time (as much as about 10-12 weeks) because the papers are usually lengthy. Journal's: Relaxed, research over months and years, reviews can be long, multiple reviews if needed; published at any time at the discretion of the Editor.