It was one of the contributors to universal suffrage in the UK. When we sent all of our young men off to fight, women were required to do traditionally male jobs. There was a lot of attrition in the First World War, but then even more in the 1918 pandemic. The combination of these two meant that there weren't enough able-bodied men after the war to send the women back home, which led to the Representation of the People Act 1918, which allowed women to vote in Parliamentary elections for the first time.
Amusingly, lots of people are making a big deal about this being the 100th anniversary of women being able to vote, when it was not the first time that women could vote (some were able to vote - and even be elected - in local elections before then) and most still could not, yet it was the first time that practically all men could vote. Women didn't get equal voting power to men until 1928. The 1928 act was made possible by the social changes that followed the end of WWI and the 1918 flu epidemic, when women became a significant proportion of the workforce.