There are several types . I use file folders for the student work and I keep a binder for me that includes the class data. In the folders I keep tests that have the benchmark. I also run reports that have program diagnostics (I Ready, Lexia, and STAR). In my binder I keep a spreadsheet of the benchmarks and the result for the diagnostics. This way I have documentation during parent conference, IEP meetings and so forth.
I have a tab for each of my students and keep any information or data gathered on each child behind their name. This includes any formal assessments or my informal observations on post-its or index cards. I also keep information such as student likes and dislikes on a page in my data binder so if there is ever a time when a student needs support or enrichment, I can be sure to incorporate their likes into activities to try and engage the student.
Having a binder is a great idea for keeping student information and data. Several years ago, I became acquainted with an online binder called https://www.livebinders.com a free platform that allows you to keep information. It works just like a hands on notebook with tabs and a place to keep information. The best part about it, is that you always have it at your fingertips instead of having to lug around a notebook.