This of course depends in part on the precise definition of word, which is somewhat subjective. However, for most practical purposes it is clear.
In essay writing and in academia, word count is necessary to provide a guide to the students and limit marker workload. Marks may be lost by students who write too much or don't write enough. Nevertheless, academic essays are difficult to control and the better ones often come out over-length.
For a typed text, a computer can quickly assess word count. For a written text, a quick way of estimating word count is to count the number of words on a typical line, and then multiply that number by the number of lines, adding up half-lines