Hi,

Here are a few comments.

Slang Informal speech, often used in a special context or by a special group, eg informal speech by computer progarmmers.

Phrase This is just a grammar term, meaning a few connected words, but not in the form of a clause

Idiom A common phrase or saying that has some special meaning. If you look at the meaning of each individual word, you will still not understand the meaning of the idiom.

Street Talk The way people, particularly uneducated and in poor economic circumstances, speak. Such people's lives are said to be centred 'on the street'. 

Colloquialism Ways that a lot of people commonly say things. Often, there are other possible ways but we have some ways that most people just seem to prefer. 'Colloquialisms' are often thought of as informal.

Best wishes, Clive