Engine Performance problem
1999 Toyota Rav4 4 cyl All Wheel Drive Automatic

hello.my question is this,my toyota rav4,under the passenger side,there are 2 vacuum hoses that were disconnected,i noticed a hissing noise and i checked under the car and these 2 hoses were disconnected,i replugged them and the idle shifted speed. i want to know what these 2 hoses do and why there was so much oil aound that area. thank you.