Vasudhaiva Kutumbakam (Sanskrit: वसुधैव कुटुम्बकम् vasudhaiva kuṭumbakam. from "vasudhā", the earth; "ēva" = indeed is; and "kutumbakam", family;) is a Sanskrit phrase  that means that the whole world is one single family. Everyone have their own worldview which is quite often different from person to person. Vasudhaiva Kutumbakam means respecting this difference. Contrary to single worldview, Vasudhaiva Kutumbakam says animals, birds, plants, trees and other organisms in the ecosystem have atma they are part of our family.
The original verse is contained in the Mahopanishad VI.71-73. Subsequent ślokas go on to say that those who have no attachments go on to find the Brahman (the one supreme, universal Spirit that is the origin and support of the phenomenal universe).
udāraḥ pēśalācāraḥ sarvācārānuvṛttimān |
antaḥ-saṅga-parityāgī bahiḥ-saṁbhāravāniva |
antarvairāgyamādāya bahirāśōnmukhēhitaḥ ||70||
ayaṁ bandhurayaṁ nēti gaṇanā laghucētasām |
udāracaritānāṁ tu vasudhaiva kuṭumbakam ||71||
bhāvābhāva-vinirmuktaṁ jarāmaraṇavarjitaṁ |
praśānta-kalanārabhyaṁ nīrāgaṁ padamāśraya ||72||
eṣā brāmhī sthitiḥ svacchā niṣkāmā vigatāmayā |
ādāya viharannēvaṁ saṁkaṭēṣu na muhyati ||73||
The above text is describing the 'lakṣaṇa' (characteristics) and behaviour of great men who are elevated to the coveted brAmhI sthiti (one who has attained Brahman while still alive. The above says:
”अयं बन्धुरयं नेति गणना लघुचेतसाम् | उदारचरितानां तु वसुधैव कुटुम्बकम् || ”
ayaṁ bandhurayaṁ nēti gaṇanā laghucētasām | udāracaritānām tu vasudhaiva kuṭumbakam ||
Discrimination saying "this one is a relative; this other one is a stranger" is for the mean-minded. For those who're known as magnanimous, the entire world constitutes but a family.
The above verse is also found V.3.37 of Panchatantra (3rd century BCE), in the in 1.3.71 of Hitopadesha - (12th century CE).
The statement is not just about peace and harmony among the societies in the world, but also about a truth that somehow the whole world has to live together like a family. This is the reason why Hindus think that any power in the world, big or small cannot have its own way, disregarding others.
Contextual meaning in the original sources of the idiom "vasudhaiva kutumbakam"
In the Mahopanishad - 6.72 the verses are used to describe as one of the attributes of an individual who has attained the highest level of spiritual progress, and one who is capable of performing his wordly duties without attachment to material possessions.
In the Panchatantra - 5.3.37, which is a collection of animal fables,the verse is uttered from the mouth of a declared fool who is killed by his naivety, suggesting it as a symbol of impracticality.
The Hitopadesha - 1.3.71 goes a step further, and not once but twice demonstrates its usage by sub-versionists, as well as tendency of the gullible to fall for it.
Current usage by Hindutva movements in India
Many hindutva organisations in India currently use the phrase 'vasudhaiva kutumbakam'. Among them is the Rashtriya Swayamsevak Sangh (RSS), a Hindu nationalist organisation that has adopted the phrase as its motto. While the Maha Upanishad merely mentions it as part of the qualities of an individual, who is a brahmayogi, Indian politicians routinely invoke the phrase during discussions on India's foreign policy, and while invoking their own record on inter-communal matters.
The concept of Vasudhaiva Kutumbakam is used in a theory presented by Marshall McLuhan as global village. The same concept is to be found in Sangam (300 - 100 BCE) Tamil purananuru poem as "யாதும் ஊரே, யாவரும் கேளீர்" (Yaadhum Oore, Yaavarum Kelir) which means, 'every country is my own and all the people are my kinsmen.' 
Dr N Radhakrishnan, former director of the Gandhi Smriti and Darshan Samiti, believes that the Gandhian vision of holistic development and respect for all forms of life; nonviolent conflict resolution embedded in the acceptance of nonviolence both as a creed and strategy; were an extension of the ancient Indian concept of Vasudhaiva Kutumbakam.
References in Modern World
Mahindra United World College of India uses this phrase as its motto.
Pranab Mukherjee emphasized the importance of values for the youth and said Indians are fortunate to have learnt from the ancestors the principle of Vasudhaiva Kutumbakam while addressing the Overseas Youth of Indian origin.
Rajendra K. Pachauri used this phrase during his acceptance speech for the Nobel Peace Prize on behalf of the IPCC on 11 December 2007. Global efforts must protect the global commons, according to him
A.R.Rahman used this phrase to thank all the people in the concert he did in Sydney on 16 January 2010.
Springdales School uses this phrase as its motto.
Symbiosis International University uses this phrase as its motto.
- Rajiv Malhotra
-  Dr N Radhakrishnan, Gandhi In the Globalised Context