Meaning:
The origin of the word “communication” is “communicare” or “communis” which means “to impart”, “to participate”, “to share” or “to make common.”
The sense of sharing is inherent in the origin and meaning of “communication.”

Definition:

Merriam Webster Dictionary: A process by which information is exchanged between individuals through a common system of symbols, signs, or behavior.

www.businessdictionary.com: Two-way process of reaching mutual understanding, in which participants not only exchange (encode-decode) information, news, ideas and feelings but also create and share meaning. In general, communication is a means of connecting people or places. In business, it is a key function of management--an organization cannot operate without communication between levels, departments and employees. 

Types of communication based on the communication channels used are:

Verbal Communication

Nonverbal Communication

Types of Communication Based on Purpose and Style

Formal Communication

Informal Communication

Verbal communication refers to the form of communication in which message is transmitted verbally; communication is done by word of mouth and a piece of writing. 

Verbal Communication is further divided into:

Oral Communication

Written Communication

Nonverbal communication is the sending or receiving of wordless messages. We can say that communication other than oral and written, such as  body language; gesture, posture, and facial expressions, is called nonverbal communication. Nonverbal communication is all about the wordless messages (body language/paralanguage) of speaker.

In formal communication, certain rules, conventions and principles are followed while communicating message. Formal communication occurs in formal and official style. Usually professional settings, corporate meetings, conferences undergoes in formal pattern.

In formal communication, use of slang is avoided and correct pronunciation is required.

Informal communication is one where there is nothing official. It’s just a casual talk. It can be known as Grapevine communication. There is no specific channel of informal communication because there is Social media, Whatsapp, SMS which are all vehicles of informal communication which can be used by people.

DIFFERENCE BETWEEN GENERAL AND TECHNICAL COMMUNICATION

GENERAL COMMUNICATION

•       Contains a general message

•       Informal in style and approach

•       No set pattern of communication

•       Mostly oral

•       Not always for a specific audience

•       Does not involve the use of technical vocabulary or graphics etc

TECHNICAL COMMUNICATION

•       Contains a technical message

•       Mostly formal

•       Follows a set pattern

•       Both oral and written

•       Always for a specific audience

•       Frequently involves jargon , graphics etc

DIFF. BETWEEN ORAL AND WRITTEN

ORAL COMMUNICATION

•       Exchange of ideas, information and message through spoken words is Oral Communication.

•       Transmission of message is speedy.

•       No record.

•       Immediate feedback can be given.

•       Probability of misunderstanding is very high.

•       It is not reliable.

•       Flexible.

•       Distortion is possible.

WRITTEN COMMUNICATION

•       Interchange of message, opinions and information in written or printed form is Written Communication.

•       Transmission of message is slow.

•       Proper records.

•       Feedback takes time.

•       Probability of misunderstanding is quite less.

•       It is reliable.

•       Inflexible.

•       Distortion is not possible.

ADVANTAGES AND DISADVANTAGES OF ORAL COMM.

ADVANTAGES

•       Less expensive

•       Saves time

•       Immediate feedback

•       Personal contact

•       Useful in difficult situations

•       Co-operative spirit

•       Useful in secret matters

•       Persuasive

DISADVANTAGES

•       No legality

•       Lack of accountability

•       Distortion of words

•       Greater scope for errors

•       Easily forgotten

•       Not useful for long distance

•       Inaccuracy and limited use

•       Sometimes creates misunderstanding.

ADVANTAGES AND DISADVANTAGES OF WRITTEN  COMM.

ADVANTAGES

•       It has legal validity.

•       It creates permanent record of evidence.

•       More precise, accurate and clear.

•       More accountable.

•       Suitable for long messages.

•       Less possibility of distortion.

•       Needs skills.

DISADVANTAGES

•       Expensive

•       Lack of flexibility.

•       Useless for illiterate people.

•       Takes times.

•       Late feedback.

•       Immediate correction is not possible.

•       Lacks personal touch. 

(Content taken from web sources)