I decided to write this post to help others have a better understanding of the different kinds of "spells" there are. And hoping that this makes the understanding of terms a bit more clear.
"Invocations" - This is a term used when the spell crafter is speaking directly to whatever he/she deeply feels to be the main source of their power, and calls upon it. The power called can differ from working to working. An invocation is usually a preporatory spell, a summoning of that power rather, and once granted with it, to use it for said working. To "invoke."
"Incantation" - Instead of calling up power, this is intensifying existing emotions. An incantation puts ones mind and psyche in the proper set that is appropriate to the working at hand.
"Bidding spell" - According to Robin Skelton's "SpellCraft", this is the most difficult spell to succeed in. A bidding spell is where the spellcrafter commands something to happen without the cooperation of others' will. For example: To make someone call, to show up at your door, sending away strangers, etc.
"Curse" - This unleashing unpleasant forces to cause some sort of destruction. (I wont go to say "dark" or "evil" forces, since members of the site beg to differ the term.)
"Blessings" - These are simply to bring peace of mind and good health to a subject.
"Graces" - These slightly differ from graces. Graces offer thanks and praise to any form of life that is to enhance the vitality of that form of life. Someone who say, prepares and meal, will grace themselves, in which using that certain power in making the mean, to then grace the others who partake in the meal, rather than asking for a blessing.
My sources come the book "SpellCraft" by Robin Skelton. Its rather a good read, and I highly recommend to anyone who wants to spruce up in their craft.