Basically phase is an angle of line joining the origin and the any point on the wave with $x$ axis of our reference frame and the word phase is defined for the single wave function. But the phase difference is defined for two waves.
To become a Certified Construction Manager (CCM), you must have a requisite amount of experience and/or education. ONE of the following: An undergraduate (4-year BA/BS level) or graduate qualifying degree. A 2-year undergraduate qualifying degree (AA/AS level) AND 4 years experience in general design/construction.
According to the U.S. Bureau of Labor Statistics, the annual average salary for a construction manager was $97,510. An associate's or bachelor's degree in construction management is often desired to become a general contractor. Experience is highly coveted. Depending on the position and type of construction, anywhere from two to seven years or more experience could be required.