What are G7 summit and G8 summit?

Talks at the G7 summit in Canada have failed to resolve deep differences between US President Donald Trump and leaders of major industrial nations. The divisions were laid bare on Friday, notably over trade.

Allies of the US are furious over Donald Trump's recent decision to impose tariffs on steel and aluminium imports, raising fears of a global trade war. It is unclear whether a communique agreed by all will be released when the meeting concludes later on Saturday. The two-day summit is being held in the town of La Malbaie, in Quebec province, reports BBC.

According to http://www.g8.utoronto.ca, since 1975, the heads of state or government of the major industrial democracies have been meeting annually to deal with the major economic and political issues facing their domestic societies and the international community as a whole.

The six countries at the first summit, held at Rambouillet, France, in November 1975, were France, the United States, Britain, Germany, Japan and Italy (sometimes referred to as the G6). They were joined by Canada at the San Juan Summit of 1976 in Puerto Rico, and by the European Community at the London Summit of 1977.

From then on, membership in the Group of Seven, or G7, was fixed, although 15 developing countries' leaders met with the G7 leaders on the eve of the 1989 Paris Summit, and the USSR and then Russia participated in a post-summit dialogue with the G7 since 1991. Starting with the 1994 Naples Summit, the G7 met with Russia at each summit (referred to as the P8 or Political Eight).

The Denver Summit of the Eight was a milestone, marking full Russian participation in all but financial and certain economic discussions; and the 1998 Birmingham Summit saw full Russian participation, giving birth to the Group of Eight, or G8 (although the G7 continued to function alongside the formal summits).

At the Kananaskis Summit in Canada in 2002, it was announced that Russia would host the G8 Summit in 2006, thus completing its process of becoming a full member. On March 2, 2014, in response to action taken by Russia in Ukraine, the G7 leaders announced the suspension of their participation in preparations for the Russian-hosted G8 Sochi Summit. On March 24, 2014, they announced they would not attend the Sochi Summit and would instead hold a G7 meeting in Brussels.