“Multi-tasking” refers to doing several tasks at the same time, and the word “while” is a useful word to connect these tasks. In this case, “while” has a temporal meaning and emphasizes the efficient use of time.
While the file is being downloaded, you can complete the survey.
You could save time if you record the number of flowers on each plant while inspecting the plants for symptoms of the disease.
Another use of “while” is to indicate acceptance, acknowledgement, or concession, similar to “although.”
While the fundamental theory remains the same, the practical implications of this finding are enormous.
While you may remind a journal to have your paper reviewed soon, you must not submit the paper to another journal during that time.
Lastly, “while” can be used to alert the reader to a contrast, similar to “whereas.”  This contrastive usage is especially helpful when a conversational tone is desired.
While antibiotics act quickly, they are often harmful to beneficial bacteria in the gut.
While coal is abundant and cheap, it is also polluting.
Although some people insist that “while” should not be used to indicate contrast, the Copyeditor’s Handbook maintains that the usage is fine so long as it does not introduce ambiguity . If there is any scope for confusion, then use “whereas” instead of “while” to highlight the contrast.
The slightly archaic “whilst” is a more formal alternative to “while” and is found mostly in British English.
 University of Chicago Press. 2010. The Chicago Manual of Style, 16th edn, pp. 299-300. Chicago: University of Chicago Press. 1026 pp.
 Einsohn A. 2006. The Copyeditor's Handbook, 2nd edn, p. 374. Berkeley: University of California Press. 560 pp.
["Publish and prosper" is a series of posts about tips for researchers whose first language is not English but who submit papers to journals published in English. The series touches upon not only writing (spelling, grammar, punctuation, usage, and style) but everything else relevant to publishing research papers that journal editors wish their authors knew.]