Sorry I can't type in chinese at work!

Some of my friends suggest me invest in mutual funds and I am very interested in it. For me, it sounds less risk than stock. Also I prefer not to buy and sell in short period, but in long term.

I checked there are different kinds of mutual funds such as stock mutual fund, index mutual, allocated mutual fund......Could any one explain the differences and recommend any of those to me?

Also, some people talk about invest in mutual funds with IRA account. We have traditional IRA, Roth IRA and rollover IRA accounts with Fidelity. Does anyone know the difference between invest with IRA account or just regular mutual funds account?

I am still dummie to the mutual fund and hope those experts here can help me.

Many thanks!!!!!!!!!!