Main differences between Structuralism and Post-Structuralism

1) Theoretical differences:

structuralism: Structuralism was a literary movement primarily concerned with understanding how language works as a system of meaning production. Focusing on the form or structure of the literary work, and the particular use of language
in the work would allow structuralists to think of language as a kind of science.
Post-structuralism, on the other hand, is less singularly defined as a movement than structuralism. Post-structuralists accuse structuralists of not following through the implications of the views about the language on which their intellectual
system is based. Post-structuralism offers a way of studying how knowledge is produced and critiques structuralist premises
. A post-structuralist approach argues that to understand an object (e.g., a text), it is necessary to study both the object itself and the systems of knowledge that produced the object.

2) Origins: Structuralism derives ultimately from linguistics. It
believes that if we observe accurately, collect data systematically
and make logical deductions then we can reach reliable conclusions
about language and the world.

 By contrast, post-structuralism derives ultimately from philosophy
which has always tended to emphasize the difficulty of achieving
secure knowledge about things. They inherit the habit of skepticism
and intensify it. 

3) Attitude to language: Structuralists accept that the world is constructed
through language in the sense that we do not have access to
reality other than through the linguistic system.

By contrast,
post-structuralism is much more fundamental in insisting upon the consequences
of the view that, in effect, reality itself is textual.

4)Practical differences: The post-structuralist literary critic is engaged in the task of

'deconstructing' the text. This process can be roughly defined as
'applied post-structuralism'. It is often referred to as 'reading against
the grain' or 'reading the text against itself', with the purpose
of 'knowing the text as it cannot know itself'. (Terry
Eagleton's definitions)

 At the same time, structuralists look for features
like parallels, echoes, and reflections. The deconstructionist looks
for evidence of gaps, breaks, and discontinuities of all kinds.