Just like the classic six in D&D, in M&M there are eight.
Strength, Stamina, Agility, Dexterity, Fighting, Intellect, Awareness, and Presence.
Like everything, this is measured in Ranks, which are on a logarithmic scale.
Are specific areas of application. For instance the Acrobatics skill is based on Agility, but you can have increased Acrobatics skill without an increase in everything based on Agility.
Used to avoid attacks and other things. Defenses are Dodge, Fortitude, Parry, Toughness, and Will.
Minor benefits that allow you to do things others can not. Like a special combat maneuver.
Superhero abilities. Mostly powers interact with the world through Effects, which are specific application of the power that you can use. An example might be a person with fire powers being able to throw a fireball effect in combat.
Things to overcome, from side effects of powers to personality quirks to harassing nemeses.
Everything in M&M is measured in ranks. Ranks move on a logarithmic scale — an increase of one Rank represents a doubling of ability. So a person with Strength 4 can lift double what a person with Strength 3 can.
You can put in that extra surge of effort when necessary, at a cost of being tired afterwards.