Moles and voles are very different creatures. Moles are underground animals that make tunnels in your lawn and garden. They are carnivores and eat mostly earthworms. Some people believe if they treat for grubs the moles will go away, but that's not true. These guys prefer earthworms. The tunnels are mostly visible in the spring when the weather is cool and moist and the earthworms are living in the top layer of soil. As the weather heats up and dries, the earthworms go deeper in the soil and the moles follow. There are several products on the market made by Liquid Fence that work pretty well, including fake earthworms that the moles eat and then the taste drives them away. They also have a spray product. Anyway, the Liquid Fence products are available in places like Home Depot, Lowe's, etc.
Voles are actually field mice. They are vegetarians and can eat the bark off young trees during the winter. They often use mole tunnels to get around, but they also nest in tall grass and meadow areas. They do tunnel a bit but nothing you'd notice. For them, trapping with mouse traps works the best. Generally voles are only problems in the winter. They look like fat mice with short tails==sort of like gray hamsters with bigger eyes.