About netweaver products

[raghucharan v]

sir,
i know about netweaver products like srm, crm, ep,xi, pi...............
but, i dont understand what does a basis guy do in all above mentioned netweaver products. what type of administration he does in those products?
what ever transactins we use for user administration in ecc5 & 6? we use same tcodes in all netweaver products for administration? like sm50, sm12. sm13, st03, st02?

or only installations of netweaver products is a basis guy work?

if we administrate in those products in what way we work? can any help in answering my question?

how do we connect netweaver products to ecc5 or 6?

[rukku]

see 70 % administration work is same for every sap product but that 30% depends upon use of that product.