Perhaps you want to know better first about muscle. Here are some definitions about muscle:

-Muscle (from Latin musculus, diminutive of mus "mouse") is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells.

-Muscle cells contain contractile filaments that move past each other and change the size of the cell.

-There are three types of muscle, which function is to produce force and cause motion:

• Skeletal muscle or "voluntary muscle" is anchored by tendons to bone and is used to affect skeletal movement such as locomotion and in maintaining posture. Though this postural control is generally maintained as a subconscious reflex, the muscles responsible react to conscious control. An average adult male is made up of 40-50% of skeletal muscle and an average adult female is made up of 30-40% (as a percentage of body mass).
• Smooth muscle or "involuntary muscle" is found within the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels, and even the skin. Unlike skeletal muscle, smooth muscle is not under conscious control.
• Cardiac muscle is also an "involuntary muscle" but is more akin in structure to skeletal muscle, and is found only in the heart.

Sixpack is a colloquial term for a well-defined rectus abdominis muscle. The rectus abdominis muscle (commonly known as "abs") is a paired muscle running vertically on each side of the anterior wall of the human abdomen.

These are some simple tips to build muscle:

1. Get stronger and get into strength training like weight lifting, push-ups, pull-ups, dips, pistols, reverse crunches, etc. More strength is more muscle. Switch to harder versions or add weight when they get easy.

2. Use free weights. You can lift the heaviest weights using barbells. More weight is more stress, thus more muscle. Free weights force you to control and balance the weight.

3. Train your legs. Squats work your whole body, they're the most important exercise. All your muscles tense when doing Squats. They work your body as 1 piece and let you lift heavy weights.

4. Get recovery with rest (muscles grow when you rest, not when you workout) and sleep (growth hormone releases when you sleep, building muscle). Aim for 8 hours sleep.

5. Eat whole foods. You'll achieve a lower body fat, so the muscles you've built show better. And the vitamin & mineral content helps recovery. Stop eating food coming from a box. Eat whole foods 90% of the time.

• Proteins: meat, poultry, fish, whey, eggs, milk, ...
• Carbs.: brown rice, oats, whole grain pasta, quinoa, ...
• Veggies: spinach, broccoli, tomato, salad, carrot, ...
• Fruits: banana, orange, apple, pineapple, peers, ...
• Fats: olive oil, fish oil, real butter, nuts, flax seeds, ...

6. Eat more. You need food for energy and for muscle growth & recovery. More frequent meals also boosts your metabolism, helping fat loss.

7. Get protein from red meat, poultry, fish, eggs and dairy. Proteins have the highest thermic effect. You need 1g protein per pound of body-weight daily to build & maintain muscle. That's 160g of daily protein if you weigh 160lbs/72kg. Eat whole proteins with each meal.

Rather than eating all of your protein or carbohydrates in one meal, it is ideal to try to spread it out over the course of the day. Five or amore small meals is the best. This is because if you eat all your protein at one time, your body won't be able to use all of it. It's about maintaining a high blood protein level so that your muscles can slowly regenerate throughout the day and while you are sleeping.

Tip to get sixpack: Strengthen your abdominal muscles and lose body fat. The concept is simple, but putting it into action is not. It will take dedication, willpower, patience and time to get a six pack but in the end, the effort is well worth it.