what is mulch?

Mulch can be any kind of material laid on top of the soil, usually to retain heat, suppress weeds and keep moisture in. Mulches include the following, the most common being bark chips, then coca shells, peat, organic soil conditioning compost, garden compost, etc. Even the "leaf litter layer" in a wood behaves like a mulch. Over time, this layer gets broken down by organisms in the soil and becomes part of the soil structure.

I have even used grass cuttings around my veggies as a mulch, shredded newspaper anything really that will stop weeds growing and as Bamboo says keep the warmth in etc.

Gena you can buy the mulches Bamboo wrote about in a garden centre or do what Ian does and make your own. You can even spread your compost on the top of the soil as a mulch. In 'no dig' gardening everything is put down on top of the soil as a mulch and the worms do the work of taking it down and in.
We regularly have to replace our top dressing of bark in the woodland area of the garden as it decomposes and breaks down into the soil. All of this adds to the fertility of said soil.

If you can find a log supplier in your area, ask if you can get some wood chippings from him/her. Left for a year in a pile, these make a great mulch to go around established plants and is slow to break down, at minimal cost. Buying bags of the stuff is a rip off in my view.
Another cheap alternative if you have the space and time to do it, is to ask a local farmer for some spoiled straw, and make a pile of it, and keep wetting it over winter. By spring you will have a fairly well rotted mulch you can use on the surface of either the vegetable or flower garden.
A more permanent mulch is to put down the permeable green membrane and cover with a thin layer of gravel or pebbles to hide it. You can make holes in it to plant through or place it tightly around existing plants.

Bottoms, as in the horsey version, produce a manure called. . . . er . . . well, you know.
Let it rot, and then spread liberally.

( er, am I allowed to write the word "Bottoms" on this site?)
Apologies if it's a bit too cheeky!

Burgundy is talking a load of sh** of course......... :~))