Mash temperatures - blood temperature equals feelingnneither hot nor cold when you stick a finger in. Mash into blood temp water, take 1/3rd of the volume and decoct it - protien rest, take one third and decoct it - sacch rest, take one third and decoct it, dextrin rest. Done. Much the same can be done with boiling water additions.
Lauter - at its simplest, a barrel/drum/trough with holes or slats in the bottom and lined with straw, grass, reeds or as nick points out, coarsley woven cloth. Or if you are talking really old beers - not at all, you ferment with all the chunks in there.
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