"Limit 1000,25" vs "limit 25 Offset 1000"
In terms of operation
SELECT id,name,description FROM tablename LIMIT 1000,25
SELECT id,name,description FROM tablename LIMIT 25 OFFSET 1000

there is absolutely no difference in the statements
siride's comment:

from https://dev.mysql.com/doc/refman/5.6/en/select.html

For compatibility with PostgreSQL, MySQL also supports the LIMIT row_count OFFSET offset syntax.


is exactly the point.

LIMIT 1000,25 means LIMIT 25 OFFSET 1000

From the same Documentation

LIMIT row_count is equivalent to LIMIT 0, row_count

YOUR ACTUAL QUESTIONS


Does this actually do the same or is my understanding wrong?
Is one slower/faster in larger tables


Since both queries are the same, there is no difference


Does the result of offset change when I do WHERE column=1 (say column has &gt;100 different values)
Does the result of offset change when I do ORDER BY column ASC (asuming it has random values)


Using LIMIT does not change any result sets. They simply navigate within the result set.
This query
SELECT id,name,description FROM tablename ORDER BY id LIMIT 1000,25

would be different from
SELECT * FROM (SELECT id,name,description FROM tablename LIMIT 1000,25) A ORDER BY id;

because the LIMIT is being applied at a different stage.
The first query returns nothing if tablename has less 1000 rows
The second query returns nothing if the subquery has less 1000 rows
CONCLUSION
You will have to sculpt the query to make sure you are sorting data at the right stage