The women's 100 metre freestyle event at the 1968 Olympic Games took place between October 18 and 19. This swimming event used freestyle swimming, which means that the method of the stroke is not regulated (unlike backstroke, breaststroke, and butterfly events). Nearly all swimmers use the front crawl or a variant of that stroke. Because an Olympic-size swimming pool is 50 metres long, this race consisted of two lengths of the pool.
Swimming at the 1968 Summer Olympics – Women's 100 metre freestyle Wikipedia