My pattern includes both and they seem to have the same video in the glossary 
Do you have a link to the pattern?
If they are used interchangeably in the pattern it probably is just an increase.
[B]Iām wondering what the difference is also ā¦[/B]
No- its from a book, Iām trying to make the leg of a knitted dinosaur. The beginning of the pattern states:
1st row: Inc, k6, inc, k1, inc, k6, inc
2nd row: Inc, purl to last st, inc
3rd row: K11, m1, k1, m1, k11 (25 sts)
Iām in the UK if that makes any difference.
Nothing in that little bit says anything about making a stitch. IMO it doesnāt mean anything different, but Iām certainly no expert. Someone who knows more will be along soon.
Thanks- according to the abbreviations in the book, āmā means make one in the 3rd row.
When A Pattern says INC. ( Increase ) I just Yarn Over
An increase can be a YO, but if you donāt want holes (lace) thatās not a good one. M1 is make 1, one type of increase; inc just indicates an increase. If the pattern doesnāt differentiate between them, use whichever you like.
Thanks guys, Iām not sure that yarn over will give a good result as this is for toy legs. Iāll try just increasing and look at the result. Thanks for the help!!
I have to put in my bit about a simple backward loop M1 or increase. 
It works very well for me. I think Amy mentions it and may say it leaves a hole, but I have to say I never notice a hole that is an issue.
If you knit through the back loop, those will tighten up, it depends on the weight of the yarn as well as the needle. Sometimes the hole is very small.
There isnāt really a ādifferenceā between M1 and Inc. M1 is a type of increase. Other increases are YO, or knit in the front and back of a stitch. If the pattern doesnāt indicate which increase is to be used, I usually do M1 because it is the least visible.
The problem with YO increase is on some patterns the hole isnāt really a good option.
At our next knitting meeting I am going to get some help learning how to kfb. I canāt figure it out just reading about it, or seeing illustrations - I have tried so many times - my perception is so out of kilter, things just donāt look the same to me as they do to the majority of the world.
In my mind, M1, or make one, means to place a backward loop over the right needle, adding a stitch using the working yarn. Inc1 would mean to do an increase of a different type, i.e., one that uses wool already in the fabric, to add another stitch, for example, knitting into the running thread or knitting into the stitch of the row below, or (ick)kfb.
I donāt know why, but I just hate kfb. I never increase that way, even if the pattern calls for it.
It could be that[I] Increase[/I] is using a stitch for the increase, as kfb. M1 adds a stitch without using a stitch. You could tell that was the case by whether or not you have enough stitches left over after the inc row.