1. Subject classification: Journals are classified by subject fields, such as natural science, social science and engineering technology. This classification method is convenient for scholars and researchers to quickly find journals related to their own research fields.

2. Classification of impact factors: impact factors are important indicators to measure the influence of journals, usually calculated in years. According to the size of impact factors, journals can be divided into high impact factor journals, medium impact factor journals and low impact factor journals. Journals with high impact factors usually represent the top research results in this field and have high academic status and influence.

3. Partition classification: Some academic databases will partition journals, such as SCI partition and JCR partition of Chinese Academy of Sciences. These divisions are usually based on the impact factors, citation times and other indicators of journals, which helps scholars to understand the academic status and influence of journals.

4. Press classification: Journals can also be classified by press, such as Springer, Elsevier, Wiley, etc. Journals from different publishing houses may have differences in publishing quality and review speed, so scholars will consider publishing house factors when choosing contributing journals.

5. Classification of open access and non-open access: With the rise of the open access movement, more and more journals began to provide open access services. There are differences in copyright and fees between open access journals and non-open access journals, and scholars need to consider these factors when choosing contributing journals.

6. Language classification: Journals can also be classified according to the language in which papers are published, such as English journals and Chinese journals. This classification method is convenient for scholars and researchers to find journals suitable for their language ability.