The Warsaw Pact (formally, the Treaty of Friendship, Co-operation, and Mutual Assistance, sometimes, informally WarPac, akin in format to NATO) was a collective defense treaty among Soviet Union and seven Soviet satellite states in Central and Eastern Europe in existence during the Cold War. The Warsaw Pact was the military complement to the Council for Mutual Economic Assistance (CoMEcon), the regional economic organization for the communist states of Central and Eastern Europe. The Warsaw Pact was created in reaction to the integration of West Germany into NATO in 1955 per the Paris Pacts of 1954, but it is also considered to have been motivated by Soviet desires to maintain control over military forces in Central and Eastern Europe. 

While the Warsaw Pact was established as a balance of power or counterweight to NATO, there was no direct confrontation between them. Instead, the conflict was fought on an ideological basis. Both NATO and the Warsaw Pact led to the expansion of military forces and their integration into the respective blocs. The Warsaw Pact's largest military engagement was Warsaw Pact invasion of Czechoslovakia (with the participation of all Pact nations except Romania and Albania). The Pact failed to function when the Revolutions of 1989 spread through Eastern Europe, beginning with the Solidarity movement in Poland and its success in June 1989.
Were NATo and the Warsaw Pact enemies of each other?
What was their relationship to one another?
Who invaded Czechoslovakia?
Did all members participate?
How many satellite states were involved in the Pact?
Where were these states located?
What was the regional economic organization for communist states in this area called?
And what did that organization compliment?
What is the Pact's informal nickname?
And its formal name?
When was it created?
As a result of what country joining Nato?
Is the Warsaw Pact formatted similarly to NATO?
What did the Soviets seek to control during the Pact's creation?
Could this be considered one of the reasons the Pact was formed?
When did the Pact end?
In which country was the beginning of the end?
With what occuring?
Was that movement ultimately successful?
What was spreading through parts of Europe at this time?
Which part of Europe was affected?
No
 there was no direct confrontation between them.
They both led to the expansion of military forces and their integration into the respective blocs.
Both NATO and the Warsaw Pact led to the expansion of military forces and their integration into the respective blocs.
Warsaw Pact
Warsaw Pact
all Pact nations except Romania and Albania
all Pact nations except Romania and Albania
seven
seven
Central and Eastern Europe
Central and Eastern Europe
Council for Mutual Economic Assistance (CoMEcon)
Council for Mutual Economic Assistance (CoMEcon)
The Warsaw Pact
The Warsaw Pact
WarPac
WarPac
the Treaty of Friendship, Co-operation, and Mutual Assistance
the Treaty of Friendship, Co-operation, and Mutual Assistance
1955
1955
West Germany
West Germany
Yes
a balance of power or counterweight to NATO
military forces in Central and Eastern Europe
military forces in Central and Eastern Europe
Yes
but it is also considered to have been motivated by Soviet desires to maintain control over military forces in Central and Eastern Europe. 
June 1989
June 1989
Poland
Poland
the Solidarity movement
the Solidarity movement
Yes
its success in June 1989.
the Revolutions of 1989
the Revolutions of 1989
Eastern Europe
Eastern Europe