Main Difference
The main difference between Hand and Arm is that the Hand is a extremity at the end of an arm or forelimb and forearm and upper arm together
Hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each “hand” and fingerprints extremely similar to human fingerprints) are often described as having “hands” instead of paws on their front limbs. The raccoon is usually described as having “hands” though opposable thumbs are lacking.Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally — for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand.The human hand normally has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the number of which varies between people, 14 of which are the phalanges (proximal, intermediate and distal) of the fingers and thumb. The metacarpal bones connect the fingers and the carpal bones of the wrist. Each human hand has five metacarpals and eight carpal bones.
Fingers contain some of the densest areas of nerve endings in the body, and are the richest source of tactile feedback. They also have the greatest positioning capability of the body; thus, the sense of touch is intimately associated with hands. Like other paired organs (eyes, feet, legs) each hand is dominantly controlled by the opposing brain hemisphere, so that handedness—the preferred hand choice for single-handed activities such as writing with a pencil, reflects individual brain functioning.
Among humans, the hands play an important function in body language and sign language. Likewise the ten digits of two hands, and the twelve phalanges of four fingers (touchable by the thumb) have given rise to number systems and calculation techniques.
Arm
In human anatomy, the arm is the part of the upper limb between the glenohumeral joint (shoulder joint) and the elbow joint. In common usage, the arm extends to the hand. It can be divided into the upper arm, which extends from the shoulder to the elbow, the forearm which extends from the elbow to the hand, and the hand. Anatomically the shoulder girdle with bones and corresponding muscles is by definition a part of the arm. The Latin term brachium may refer to either the arm as a whole or to the upper arm on its own.
Hand (noun)
The part of the fore limb below the forearm or wrist in a human, and the corresponding part in many other animals.
“Her hands are really strong.”
Hand (noun)
That which resembles, or to some extent performs the office of, a human hand.
Hand (noun)
A limb of certain animals, such as the foot of a hawk, or any one of the four extremities of a monkey.
Hand (noun)
In linear measurement:
Hand (noun)
An index or pointer on a dial; such as the hour and minute hands on the face of an analog clock, which are used to indicate the time of day.
Hand (noun)
Four inches, a hand’s breadth.
Hand (noun)
A side; part, camp; direction, either right or left.
Hand (noun)
Power of performance; means of execution; ability; skill; dexterity.
Hand (noun)
An agent; a servant, or manual laborer, especially in compounds; a workman, trained or competent for special service or duty; a performer more or less skillful.
“an old hand at speaking;”
“large farms need many farm hands”
Hand (noun)
An instance of helping.
“Bob gave Alice a hand to move the furniture.”
Hand (noun)
Handwriting; style of penmanship.
“a good hand”
Hand (noun)
A person’s autograph or signature.
“Given under my Hand and Seal of the State this 1st Day of January, 2010.”
Hand (noun)
Personal possession; ownership.
Hand (noun)
Management, domain, control.
“in safe hands;”
“in good hands;”
“He lost his job when the factory changed hands.”
“With the business back in the founder’s hands, there is new hope for the company.”
“With John in charge of the project, it’s in good hands.”
Hand (noun)
That which is, or may be, held in a hand at once.
Hand (noun)
Three inches.
Hand (noun)
The set of cards held by a player.
Hand (noun)
A round of a card game.
Hand (noun)
A bundle of tobacco leaves tied together.
Hand (noun)
Applause.
“Give him a hand.”
Hand (noun)
A Native American gambling game, involving guessing the whereabouts of bits of ivory or similar, which are passed rapidly from hand to hand.
Hand (noun)
The small part of a gunstock near the lock, which is grasped by the hand in taking aim.
Hand (noun)
A whole rhizome of ginger.
Hand (noun)
The feel of a fabric; the impression or quality of the fabric as judged qualitatively by the sense of touch.
“This fabric has a smooth, soft hand.”
Hand (noun)
Actual performance; deed; act; workmanship; agency; hence, manner of performance.
Hand (noun)
Agency in transmission from one person to another.
“to buy at first hand (from the producer, or when new);”
“to buy at second hand (when no longer in the producer’s hand, or when not new);”
“It’s not a rumor. I heard it at first hand.”
Hand (noun)
Rate; price.
Hand (verb)
To give, pass, or transmit with the hand, literally or figuratively.
“He handed them the letter.”
“She handed responsibility over to her deputy.”
Hand (verb)
To lead, guide, or assist with the hand; to conduct.
“to hand a lady into a carriage”
Hand (verb)
To manage.
Hand (verb)
To seize; to lay hands on.
Hand (verb)
To pledge by the hand; to handfast.
Hand (verb)
To furl.
Hand (verb)
To cooperate.
Arm (noun)
The portion of the upper human appendage, from the shoulder to the wrist and sometimes including the hand.
“She stood with her right arm extended and her palm forward to indicate “Stop!””
Arm (noun)
The extended portion of the upper limb, from the shoulder to the elbow.
“The arm and forearm are parts of the upper limb in the human body.”
Arm (noun)
A limb, or locomotive or prehensile organ, of an invertebrate animal.
“the arms of an octopus”
Arm (noun)
A long, narrow, more or less rigid part of an object extending from the main part or centre of the object, such as the arm of an armchair, a crane, a pair of spectacles or a pair of compasses.
“The robot arm reached out and placed the part on the assembly line.”
Arm (noun)
A bay or inlet off a main body of water.
“Shelburne Bay is an arm of Lake Champlain.”
Arm (noun)
A branch of an organization.
“the cavalry arm of the military service”
Arm (noun)
Power; might; strength; support.
“the arm of the law”
“the secular arm”
Arm (noun)
A pitcher
“The team needs to sign another arm in the offseason.”
Arm (noun)
One of the two parts of a chromosome.
Arm (noun)
A group of patients in a medical trial.
Arm (noun)
A weapon.
Arm (noun)
heraldic bearings or insignia
“The Duke’s arms were a sable gryphon rampant on an argent field.”
Arm (verb)
To take by the arm; to take up in one’s arms.
Arm (verb)
To supply with arms or limbs.
Arm (verb)
To supply with armour or (later especially) weapons.
Arm (verb)
To prepare a tool or a weapon for action; to activate.
“Remember to arm an alarm system.”
Arm (verb)
To cover or furnish with a plate, or with whatever will add strength, force, security, or efficiency.
“to arm the hit of a sword; to arm a hook in angling”
Arm (verb)
To furnish with means of defence; to prepare for resistance; to fortify, in a moral sense.
Arm (verb)
To fit (a magnet) with an armature.
Arm (adjective)
Poor; lacking in riches or wealth.
“He’s neither poor nor arm.”
Arm (adjective)
To be pitied; pitiful; wretched.
Hand (noun)
the end part of a person’s arm beyond the wrist, including the palm, fingers, and thumb
“the palm of her hand”
“he was leading her by the hand”
Hand (noun)
a prehensile organ resembling the hand and forming the end part of a limb of various mammals, such as that on all four limbs of a monkey.
Hand (noun)
a person’s arm, including the hand
“that dog bite me on mi hand, right below the elbow”
Hand (noun)
operated by or held in the hand
“hand luggage”
Hand (noun)
done or made manually rather than by machine
“hand signals”
“a hand-stitched quilt”
Hand (noun)
a round of applause
“his fans gave him a big hand”
Hand (noun)
a person’s handwriting
“he inscribed the statement in a bold hand”
Hand (noun)
a pledge of marriage by a woman
“he wrote to request the hand of her daughter in marriage”
Hand (noun)
a pointer on a clock or watch indicating the passing of units of time
“the second hand”
Hand (noun)
used in reference to the power to direct something
“the day-to-day running of the house was in her hands”
“they are taking the law into their own hands”
Hand (noun)
an active role in achieving or influencing something
“he had a big hand in organizing the event”
Hand (noun)
help in doing something
“do you need a hand?”
Hand (noun)
a person’s workmanship, especially in artistic work
“his idiosyncratic hand”
Hand (noun)
a person who does something to a specified standard
“I’m a great hand at inventing”
Hand (noun)
a person who engages in manual labour, especially in a factory, on a farm, or on board a ship
“a factory hand”
“the ship was lost with all hands”
Hand (noun)
the set of cards dealt to a player in a card game
“the situation does not give them a strong hand at the negotiating table”
“he’s got a good hand”
Hand (noun)
a round or short spell of play in a card game
“they played a hand of whist”
Hand (noun)
the cards held by a declarer as opposed to those in the dummy
“declarer won in hand and led ♣J”
Hand (noun)
a unit of measurement of a horse’s height, equal to 4 inches (10.16 cm).
Hand (noun)
a bunch of bananas
“mottled hands of bananas”
Hand (noun)
a forehock of pork.
Hand (verb)
pick (something) up and give it to (someone)
“I handed the trowel back to him”
“he handed each man a glass”
Hand (verb)
make (abusive, untrue, or otherwise objectionable remarks) to (someone)
“all the yarns she’d been handing me”
Hand (verb)
hold the hand of (someone) in order to guide them in a specified direction
“he handed them into the carriage”
Hand (verb)
take in or furl (a sail)
“hand in the main!”