What are the types of reports that we have in Salesforce?

We have four types of report formats available in Salesforce:
1. Tabular Reports: Simple listing of data without any subtotals. This type of reports provide you most basically to look your data. Use tabular reports when you want a simple list or a list of items with a grand total.
2. Summary Reports: This type of reports provide a listing of data with groupings and sub totals. Use summary reports when you want subtotals based on the value of a particular field or when you want to create a hierarchically grouped report, such as sales organized by year and then by quarter.
3. Matrix Reports: This type of reports allow you to group records both by row and by column. A comparison of related totals, with totals by both row and column. Use matrix reports when you want to see data by two different dimensions that aren’t related, such as date and product.
4. Joined Reports: Blocks of related information in a single report. This type of reports enable you to adopt five different blocks to display different types of related data. Each block can own unique columns, summary fields, formulas, filters and sort order. Use joined reports to group and show data from multiple report types in different views.