Don't buy the 226BW. It's a good monitor, but only if you get an "S" panel. That monitor uses three different kinds of LCD, made by Samsung, Chi Mei, and AUO. Samsung puts an S, C, or A on the monitors label, depending on which panel it contains. If you calibrate the screen the C and A models look pretty much the same as the S model, but there are other problems as well, such as ghosting, banding, backlight bleeding, ect.
however in regards to the opening question, ""Active Matrix TFT LCD" vs. "a-si TFT/TN"?" they are for simplicities sake the same, both are active matrix, both are TFT tech, and both are TN panels" different jargon by different companies for the same technology. active matrix TFT LCD w/TN panel vs. active matrix a-si TFT LCD w/TN panel. since all that matters to me is TN/*-*VA/IPS panel the other terms might as well be the same.