Here's a good place to start - really brief video showing the key outline ideas.

Link to Video: https://youtu.be/dhhdPgVzkwU

All sociology springs from Auguste Comte, and Functionalism is the first formalised theory of society to be thought out. It was an attempt to create theory of EVERYTHING in society, it is a macro-theory and looks at how institutions are linked to each other.

A brief overview can be found here:
https://www.sociologyguide.com/theoretical-perspectives-in-sociology/functi...

Remember - this is a 'rough guide' it doesn't cover all the intricacies - but it should give you a reasonable overview of the 'headlines'!

Durkheim, writing towards the end of the 19th C studied the role of religion in societies.

From these studies came the belief that social order was a product of shared beliefs, values, norms and traditions within society. He called these the 'collective conscience' which through their shared nature led to conformity of thought and behaviour.

These shared beliefs and values brought with them a sense of social solidarity, working together for the common good. Conformity is rewarded by society, whereas non-conformity receives sanctions.

This social solidarity is both formed and encouraged by institutions such as education, law, religion, government, the family - they all have a role to play in creating and maintaining the consensus - as individuals we participate in these institutions and are therefore part of that process.

Change within society is possible where everyone consents to it, if change is too rapid then confusion follows, a sense of disconnect from society; Durkheim calls this 'anomie'

You can find more on Durkheim at the excellent ThoughtCo site
https://www.thoughtco.com

In the 1950s comes Parsons who looks at society through the lens of the organic analogy, that society is like a human body - it requires every aspect to complete its role (function) or the whole becomes dysfunctional.

In the human body our organs are interconnected and interdependent

Bodies can evolve and adapt, so if one part changes (that is a positive, rather than a negative change) then the rest will adapt to accommodate that change.

However, if one part becomes infected or ill then it can cause damage to other parts of the system. For example if there is too much crime or if the family doesn't fulfil its function effectively.

Not all Functionalists agree on just how helpful institutions are to all individuals.

Merton points out that the assumption that society is working in a 'traditional' format may not be true - e.g. must primary socialisation necessarily be performed within a traditional nuclear family to be successful?

The idea of functional unity is flawed in Merton's view - i.e. that all parts of society are completely interdependent, he proposes that it's possible for one part of society to change or even disappear and for the whole to remain relatively unchanged, or at least continue to be functional.

He also challenges universal functionalism - perhaps not all aspects of society, not all institutions are acting positively for all groups - there is an explicit link here to ideas in conflict structuralism.

Finally Merton talks about manifest and latent functions in society - manifest means the intended consequence and latent the unintended consequence. For example, a ritual may not have the intended outcome but performing that ritual as a group may help people to feel more part of that group, more inclined to help each other.

Marxists: Functionalists don't take into account difference and conflict, specifically class based. They also point out that whilst Functionalists see consensus and positivity, conflict exists between groups who are not treated equally. They believe that actually Functionalism is helping to maintain and uphold inequality and injustice with its emphasis on consensus.

Action Theorists: people don't simply follow the guidelines, free choice exists and socialisation is a two-way street. Not everyone conforms, in fact most people are non-conformist in some way. Society on a large scale is not the most important influence on people's behaviour.

Feminists: they're not looking at inequalities between the sexes or how 'traditional' society may in fact support the patriarchy rather than be a consensus which benefits everyone.

Postmodernists: society today is massively diverse, value consensus doesn't reflect the idea of a variety of lifestyles/values; a macro theory cannot explain the quantity of difference which exists.