Difference between Precis Writing and Summary Writing

 It is very difficult to differentiate between precis writing and summarizing because 'precis and summary are often treated synonymously.although they are same, some differences can be discussed as below:

1. A precis is a concised summary or abstract whereas a summary is normally one third or more/ less of the original passage, so they differ in the length. Normally a precis is shorter than summary. 
2. A precis include only principal theme whereas a summary includes all the main points.
3. precis writing has to be the language of the text itself whereas summary writing can be done in the language of the writer.
4. Writing a precis should follow the order of original text but it is not basically necessary for summary writing.
5. Precis writing is always written form whereas summary can be written or spoken.