I can think of three meanings: The first is about putting things in sequence. For example it is common to write a list of names 'in alphabetical order'. I can say 'the names are in order'. The second is a more figurative version of the first. It means getting things organised. It is commonly used for situations such as financial affairs, or how a business works. For example: 'We need to get our stock management system in order' ie. it's a mess now, and it needs to be organised. The third is about doing one thing to achieve something else. It generally uses the construction 'in order to + infinitive verb'. It is quite purposeful in its meaning, and is used frequently in a work context. eg. I go to the gym in order to get fit. eg. We train the staff well in order to reduce customer complaints (However - 'I go to the movies in order to have fun' sounds wrong. 'In order' is too formal here. 'I go to the movies to have fun' is better in this less purposeful situation.)

Not sure what you mean there. Like, as part of a larger phrase?