Integrated marketing communications means integrating all promotional efforts in harmony so that they provide consistent messaging to consumers. This allows the benefits of each channel to be utilised and thus adds value, creating synergy which allows the audience to comprehend your message clearer. There is a huge difference between using only one channel and integrating many. Most brands now use integrated marketing communications to target their consumers. 

This very much depends on what is being 'integrated'. I wrote a section on this in my chapter 'Marketing Communications in a Digital World'. https://goo.gl/3vN5VT

What promotional efforts are we talking about - the creative  - same message in different channels? The strategic objective of the campaign? Or is it resource integration internally, so you don't have separate teams dealing with social media and out of home advertising, for example? 

More questions, but I hope it helps in understanding these concepts.

Dear Julia and Cherniece,

Thank you for your answers, as both of you answered it correctly then also I will add something more to that. That is integrating every opportunity, sources within and outside the company and all the appropriate tools based on the company’s brand(s) into a cost effective communication program with maximum impact on consumers. Also we need to sustain it with continuous interaction with consumers. So that it will create brand identity and more brand value there by higher brand equity in the consumers mind.

Thank You.