Collate is a printing term that means to assemble in a logical order. It is typically used when referring to multiple copies of a document, such as a book or a report. For example, if you are printing 10 copies of a 20-page document, you would want to collate them so that each copy contains pages 1-20 in order. This is opposed to printing 1 copy of the document, then 2 copies of the document, then 3 copies of the document, and so on.
Collating can be done manually or electronically. Manually collating a document is a time-consuming process, especially if you have a large number of copies to print. Electronically collating a document is much faster, as the printer will do all the work for you.
If you are unsure whether or not your printer can collate, check the manual or contact the manufacturer. Many newer printers have this feature, but some older models may not.