Defining relative clauses...

  • add essetial information about the nouns, and
  • can be introduced by the relative pronoun that in informal speech.

Non-defining relative clauses...

  • add extra information about the noun,
  • are enclosed by commas,
  • can be used with quantifiers and numbers followed by the relative pronoun,
  • can't be introduced by the relative pronoun that, and
  • can refer to a whole sentence.

Using a present participle clause can give a reason for the action in the main clause.

Perfect participle forms, Having + past participle, show that the action in the participle clause was finished before the action in the main clause.

http://www.bbc.co.uk/learningenglish/english/course/upper-intermediate/unit-17/session-1

Participle clauses are clauses that begin with present or past participles. Participle clauses can be used when the participle and the verb in the main clause have the same subject. Participle clauses with past participles have a passive meaning.

http://www.bbc.co.uk/learningenglish/english/course/intermediate/unit-27/session-2/activity-3

http://www.bbc.co.uk/learningenglish/english/course/towards-advanced/unit-29/session-1

Two types of relative clause:

  • defining: give the information that directly identifies what is being talked about,
  • non-defining: add more information about nouns, do not identify the noun being talked about.

https://en.oxforddictionaries.com/grammar/relative-clauses