Difference between conference paper and journal paper
Conference papers refer to articles that are written with the goal of being accepted to a conference: typically an annual (or biannual) venue with a specific scope where you can present your results to the community, usually as an oral presentation, a poster presentation, or a tabled discussion. The review process for conference papers is typically within a fixed window: everyone submits for a certain deadline, then the review committee (program committee) collaborates to review and discuss papers, then all authors are notified with accept/reject at the same time. Since the review process has a fixed schedule (to meet the schedule of the physical meeting), conference review times are quite predictable.

Conference papers are typically published in collections called "proceedings": sometimes these are printed by university presses, by professional organizations, by big-name publishers, or simply online.

Journal papers refer to an article that's published in an issue of the journal. The frequency of issues for different journals varies from one-a-month to once-a-year, or anything in between; it may not even be regular. The review process for journals often does not have a fixed deadline or schedule: though journals may promise things like "reviews in six weeks", in my experience, this rarely if ever holds true. However, instead of conferences that typically have only accept/reject decisions, journals typically have a rolling review schedule and reviewers can opt to ask the authors for revisions, meaning that there might be multiple review phases (often limited to three, at which stage the paper is rejected/accepted).

Since conference papers have a fixed schedule and provide the authors a venue for discussion and feedback, they are generally for earlier-term work or for "announcing/marking an idea", or for finding collaborators. Furthermore, conference papers tend to have fixed page-limits, which restricts the content to preliminary findings.

Journal papers tend to have generous page-limits (or none at all), but typically require the work to be more comprehensive and self-contained in return.

In general, in most fields, papers in well-recognized journals tend to have more prestige than papers in well-recognized conferences (esp. in terms of metrics). But this is a simplification.

While in some fields, conference papers are akin to talk abstracts, in areas like computer science, conference papers can be very meaty and there is a high churn of papers in conferences. Top conferences can have acceptance rates around 10%, and as such, A+ conference papers are often held in high regard within the community: these venues are far more competitive than many of the best journals. Still, even in the CS area, metric-wise (for hiring, positions, funding, etc.), journals will often still count for more than a conference following the norm in other academic fields.