Twitter help with hash tag!?

[Lexi . (:]

When you use a hashtag its like when you want to use a word or sentence that other people can look at . So like if you send a tweet that says , " Had the best day ever ! #ilovemylife " then when you or other people click on it , it shows all the tweets that relate to that hashtag . You can't use spaces or characters in a hashtag thoo , not sure about numbers .