Causative verbs express an action which is caused to happen. In other words, when I have something done for me I cause it to happen. In other words, I do not actually do anything, but ask someone else to do it for me. This is the sense of causative verbs. Intermediate to advanced level English learners should study the causative verb as an alternative to the passive voice.

Causative Verbs :
Jack had his house painted.
This sentence is similar in meaning to : Someone painted Jack's house. OR Jack's house was painted by someone. Causative verbs express the idea of someone causing something to take place. Causative verbs can be similar in meaning to passive verbs.
Examples: 
My hair was cut. (passive)
I had my hair cut. (causative)
Both 'make' and 'have' can be used as causative verbs.

Make
'Make' as a causative verb expresses the idea that the person requires another person to do something.

Construction Chart
Subject + Make + Person + Base Form of Verb

Examples:
Peter made her do her homework.
The teacher made the students stay after class.

Have
'Have' as a causative verb expresses the idea that the person wants something to be done for them. This causative verb is often used when speaking about various services. There are two forms of the causative verb 'have'.

Construction Chart : Use 1
Subject + Have + Person + Base Form of Verb

Examples:
They had John arrive early.
She had her children cook dinner for her.

Construction Chart : Use 2
Subject + Have + Object + Past Participle

Examples:
I had my hair cut last Saturday.
She had the car washed at the weekend.
Note: This form is similar in meaning to the passive.

Get
'Get' is used as a causative verb in a similar way as 'have' is used with the participle. This expresses the idea that the person wants something to be done for them. The causative verb is often used in a more idiomatic manner than 'have'.

Construction Chart
Subject + Get + Person + Past Participle

Examples:
They got their house painted last week.
Tom got his car washed yesterday.

Source : http://esl.about.com/od/grammarstructures/a/causative.htm