Index can be defined by some of our sensory feature through vision, hearing, smell to indicate what is happening by looking at a thing.Example of Index :1)When you see a bright blue sky, it is an index of a sunny and good weather day.2)when you see a person with a greenish face, it is an index of a person getting sick.Symbol is of a unique mark that represent some kind of information.Example of Symbol :1)When you see a red traffic light, it is a symbol that tell us to stop.2)When we see the exclaimation mark, we know it is a symbol to tell us to be careful.Icon is the simplest of which it is a pattern that physically represent what it really standsfor.Example of Icon :1)A human picture in messenger is a example of an icon.2)The picture of a speaker on the computer screen is an icon for the volume/sound control.
From my understanding, an index is an indication. For example, when we see smoke, we will relate it to fire Or when we hear thunder, it's relate to raining. A icon is a mode in which the signifier is perceived as resembling or imitating the signified. For example, a portrait, a cartoon, a scale-model, sound effects in radio drama, or imitative gestures. Lastly, a symbol carries meaning is a purely arbitrary way. In Brief, Symbol is a representative of a meaning. For example, language in general, alphabetical letters, punctuation marks, numbers, morse code, traffic lights.
ＩＣＯＮ is the simplest since it is a pattern that physically resembles what it `stands for'.ｅｘａｍｐｌｅ ：A picture of your face is an icon of you.ＩＮＤＥＸ is defined by some sensory feature, A, (something directly visible, audible, smellable, etc) that correlates with and thus implies or `points to' B, something of interest to an animal.ｅｘａｍｐｌｅ ：Ｆor a fish in the sea, the direction of greater light is the direction of warmer water．ＳＹＭＢＯＬ ｉｓ a noun word in a human language．ｅｘａｍｐｌｅ ：You and your baby will also freely use the word KITTY when a cat is NOT around (so the correlation between KITTY and the cat is a very weak). [If your dog knows the `word' TAKE-A-WALK, try just discussing taking a walk in earshot of the dog and see what happens! Dogs have no grasp of `Talking about taking-a-walk'. That's because take-a-walk is only an indexical sign for your dog, not a symbol as it is for you and your baby.]
SYMBOLIC: is content words that get meaning.For example the word ‘house’ does not look anything like a house, but has come to signify ‘house’. A red octagon may be a symbol for "STOP". A flag is a symbol of a country. A country can have more than one symbol.ICON: represents similarity, a picture in your facebook is an icon of you. A mobile and computer icon button!INDEX: Defined by some sensory feature, directly visible, audible, smell able, etc, to associate with something in thinking! for example if someone is walking down a street and suddenly encounters the smell of roast chicken, he or she might find the concept of roast chicken coming to mind.
INDEX:Is through sight, smell, taste, touch and hearing that You can think of something. for example:When you see a girl crying, you know she was very sadSYMBOLIC: is something such as a particular mark that represents some piece of information. For example:Dove symbolizes peace,When we see a sign of no smoking, we know that there can not smoke.ICON:Have to refer to the meaning of graphic symbols, icons can quickly convey information to facilitate memory characteristics.For example:Male and female toilet signs, all kinds of traffic signs, etc..
Index：Index should be the one can tell us something, as an omen, a phenomena of something. For example, When you smell a scorching smell, you know that something is burning and probably already for a long time. Or when you see someone is crying, you know that he or she is sad at that moment. Icon: Icon is more concrete, should be concrete thing to represent something. Such as the logo of Apple Inc. and the dustbin on the desktop represented Recyle Bin.Symbol: Symbol is very arbitrary, as a person's feeling or opinion of something, such as when a person see one item, what come to his or her mind, for him or her, this item is a symbol of that thing. For example, a red heart is alway a symbol of love and a nickname is a symbol of a person.
based my research :P 3 modes (index, icon and symbol)are not fixed mutually, sign can be a symbol, an icon can be an index or in any combination. index : connected in the some way either physically or causally, also can figure out the relationship eg. Eiffel Tower located at Parisicon :physically or perceptually resembles the signified, where can recognize the object immediately eg. Eiffel Tower icon of Paris.symbol :does not resemble the signified but must learn the relationship (conventional relationship) eg. Eiffel Tower was a symbol of attraction for tourists to come to Paris, also, can symbolized as romance town.With one object, it's can classified into different of mode.