What is the difference in colic and tying up

I have heard so many different things I don't know what to believe!

The 2 are completely different...

COLIC: Colic is not a disease in itself. Colic is a symptom of abdominal pain. Colic can be mild or severe, and take a number of forms. Impaction colic is caused by a blockage in the intestine. Gases that build up in front of an impaction may cause painful gaseous distention. Gaseous distention can also be caused by the fermentation of feed in the stomach if the horse has gorged itself. Intestines can twist, telescope or become twisted around the tissue that attaches them to the abdominal cavity. This will cause violent colic symptoms. The blood flow in the intestine becomes obstructed. When a horse colics first they would be walked, given bran mash if they will eat it, tubed/oiled by the vet, given bantamine for pain and last resort would be colic surgery or putting the horse down.

TYING UP: Muscle issue. This is a muscular problem in the horse caused by the inability within the muscle tissue to eliminate the lactic acid that builds up during exercise quickly enough and allows it to reach toxic levels.This typically starts with varying degrees of discomfort ranging from stiffness and mild cramps to severe cramping and inability to move to flat out laying there in very severe cases. In mild cases hind leg stiffness and a shuffling gait may be seen. Pain may be found by palpation of the back and gluteal muscles. Severely affected animals may suffer marked muscle cramping or inability to move. Affected horses become very anxious, they may sweat profusely, have elevated heart and respiratory rates. Signs of extreme pain may be evident if it is attempted to move the horse. If the horse urinates, the urine may be discolored red with myoglobin, a breakdown product of muscle. You get a blood test done to positivelty identify the horse has tyed up. If this happens Stop exercise immediately. Do not keep him walking. Moderate to severe cases should be seen by your vet. Provide the horse with water and add electrolytes if the horse will drink the solution.