A compound statement is a group of statements enclosed within a pair of curly braces ({ }) and is often also called a block statement. The statements within the block may be of any statement type (including (again) compound statements). This allows statements to be embedded or nested within other statements. A compound statement does not end with a semicolon after the closing }.
Code example
{
a = 0;
a++;
b = 3 + c;
y = (a * x) + b;
printf("Speed = %f", x);
}