Status (/ˈsteɪtəs/) - relative social or professional position; standing.

It's always helpful to consolidate the simple facts about each character in a text before studying it so that when names are mentioned they will become familiar. The characters, especially in a play, are extremely vital in telling the story which may seem a lot clearer when you know who is who. Especially in this play where there aren't many characters its probably a good idea to look over character profiles before thinking about analysing as not doing this makes everything 10x harder than it needs to be.

The Inspector

The clue's in the title. An Inspector Calls gives away that the Inspector is a vital character in the play, although this doesn't mean that he is the most reoccurring character. In fact, even after reading the whole play, there is a high level of uncertainty as to who this inspector actually is. 

The inspector arrives unexpectedly and is very different compared to the class of the Birling's. He is described as authoritative and imposing, and delivers a speech at the beginning of the play about social responsibility; which is forgotten by the other characters after Gerald finds out it was a hoax. As an inspector, it is not surprising that he asks a lot of questions. It's his job. He also reveals key information which adds more drama to the plot. His timings are crucial and the language he is given by Priestley is emotive, but not to create sympathy for him, but for EvaDaisy.

Arthur Birling
Arthur is the 'man of the house.' Without his wealth, he wouldn't be enjoying the luxuries of living the rich life. He is the boss of his own company and desperate to join forces with his potential son-in-law's family business. He seems to care more about his social status than the well-being of others which is why the reader is most likely to despise him.
Undoubtedly he is a very successful man and has worked hard to get himself to his position as he was not born into a wealthy family. He is optimistic about the future and is not affected by the "silly little war scares." He is a very ambitious man with high hopes of what Sheila and Gerald's marriage will bring to his company.
Despite having an extremely impressive work ethic, it seems that that is all his mind is set upon. The audience/reader can understand that Arthur refuses to accept the responsibility of the death of EvaDaisy. He doesn't believe in "community" and all that "nonsense" and not only refused the request of a pay rise, he personally fired the people who requested; one of those being EvaDaisy.

Sybil Birling

Sybil is the wife of Arthur, and is involved with the Brumley Women's Charity Organisation which only support "deserving cases." She, too, won't accept responsibility of the death of the young girl despite having the power to give her the money that she desperately needed. 
She has a high social status and lives by strict standards; she is always reminding her family to have better manners and she is prejudiced against people of lower social standards. She doesn't want to be involved with women "of that sort" and blames the father of the unborn child for EvaDaisy not having any money without realising she blames her own, alcoholic, son. 
Despite everything that happens in the play, Sybil doesn't change in attitude at all, unlike her children, who feel guilt toward their contribution. Sybil is self-centred and doesn't learn from the inspectors message and her only regret was not asking the inspector "a few questions" 

Sheila Birling

Sheila is the daughter of Arthur and Sybil and is expected to marry Gerald Croft. Sheila changes the most out of all the characters; seeming childish at the beginning of the play ("Look - Mummy - isn't it a beauty") and then maturing into a more sensible, insightful woman. 
Sheila takes the inspector's side for most of the play, and almost does the job for him. She asks Gerald a lot of questions about Gerald's affair with EvaDaisy, she reveals Eric's drinking problem to her mother and she moves the discussion on quickly by startling the listeners just like the inspector does. 
I think its easy to forgive Sheila for what she had done to Eva because her involvement with Eva seems to be more or a lack of maturity rather than being spoilt, and because the audience can see Sheila's progression in maturity throughout the play, it shows us that she has changed her ways and regrets her actions.

Eric Birling

Eric seems to be the most irresponsible character in the play. He has turned away from his family and taken up drinking - he is isolated from the rest of his family.
He met EvaDaisy in the Palace bar (the same place Gerald met her) and got her pregnant. He steals money from his fathers business to help support her without him knowing which altogether makes it seem like he has done the most damage. 
Eric doesn't seem to be normal, most probably due to his drinking habits, but the Arthur seems more concerned about him stealing money than his health. However, at the end of the end of the play, Eric's reputation is damaged, but Gerald's - who did a similar thing - is not affected.

Gerald Croft
Gerald is the son of Arthurs competition, Croft Limited, and is very respectable for his class. Gerald (alike Sybil and Arthur) doesn't change in the play, which shows that the younger generation can be just as selfish. He doesn't learn any lessons after he finds out the inspector was a hoax, saying "Everything's alright now, Sheila"
Gerald met EvaDaisy at the Palace bar and kept her as his mistress until he decided to discard her. He had this power because of the difference in social statuses, but the audience may not feel like they should blame Gerald for EvaDaisy's death because she didn't blame him. He may have had feelings for her but she definitely did, so breaking her heart and making her homeless probably didn't make her feel any better than she did before. He says that "young women ought to be protected against unpleasant and disturbing things" yet contradicts himself in the way that he treated EvaDaisy.

Eva Smith/Daisy Renton
Eva and Daisy may not be the same person, but she is the main subject of conversation in the play and her involvement with the other characters is what creates meaning in the play.
Inspector Goole speaks for EvaDaisy because we assume that she is not alive. EvaDaisy represents the powerless members of society at that time - silent and invisible. Goole tries to teach the Birling family about social responsibility by saying "we are members of one body" and "there are millions... of Eva Smiths and John Smiths", which is trying to prove that although one member of society has gone, doesn't mean that we should disregard them, but associate them with everyone else. Of course this lesson of accepting everyone in society is still around today, but especially at the time in which this was written, it was important to Preistley to make his audience aware of the social diversities and how they affect people.

Edna
So, according to some people, Edna has extreme significance in the play. In my opinion (and in many others opinion) Edna isn't that important in the play but her lack of presence in the play may show the diversity of upper and lower class people. As the majority of characters in the play are of a middle/upper class, it shows that they are prejudiced towards people of lower class. Along with EvaDaisy, Edna resembles those who were not respected in the same way higher class people were, and that society saw them as irrelevant people.